|
AGS:
|
AGS, or the American Gem
Society Laboratories, are one of the official gemological laboratory that
grades the cut of a diamond.
|
|
Alloy:
|
Metals that are added to
gold to provide strength and color variety, e.g., copper added to gold
produces a "rose-gold" used widely in Victorian era. |
|
Anniversary
Band:
|
Traditional gift from
husband to wife marking an anniversary or a special expression of love.
Stones set across the band in groups of three or more are standard. |
|
Appraisal:
|
An estimation by a
qualified individual of the value of property. In jewelry, an estimate of
the replacement value of a piece of jewelry by a qualified jeweler, usually
for insurance purposes.
|
|
Asterism:
|
Light rays form
star-like effect in certain cabochon cut gemstones. They can be four-rayed,
6-rayed or (rarely) 12.
|
|
Band
Detailing:
|
Engraved - Decorating metal by cutting lines into the surface with a sharp graver.
Milgrain - A band of metal that is decorated with tiny beads of metal.
|
|
Bracelet Types:
|
Bangle - A rigid or inflexible bracelet, either solid or hinged to open with a clasp.
Cuff - A wide, solid bracelet usually with minimal decoration.
Charm- links with small
mementos attached by "jump" rings; American tradition of filling
the bracelet with tiny memories has never gone out of style.
"Charms" refers to the little molded, engraved or stone-set
pieces making up the jingle of the bracelet.
Line - A full length of single row diamonds forming a bracelet.
Omega - A solid looking chain with close fitting rectangular links.
'S' Tennis - A tennis
bracelet with "S" shaped links between each diamond creating a
flexible bracelet.
Tennis - A flexible in line diamond bracelet.
|
|
Bridal Set:
|
The traditional set of
two rings that fit together- the engagement ring and the wedding
band.
A Trio Set
is three rings in a matched set,
an engagement and wedding band for the bride and coordinating wedding band
for the groom. |
|
Brilliant Full
Cut:
|
This traditional
faceting or cutting style for diamonds which improves the optical effect.
The perfection of the diamond as a gem was only realized by the modern
full-cut brilliant. Developed in 1910, its characteristics are: round
girdle, 32 facets plus the table on the crown or upper part of the diamond
and 24 facets plus, sometimes a culet (point) on the pavilion-- the lower
part. The word "brilliant" used alone refers only to diamonds. On
any other stone the name of the mineral must be used with it, e.g., a
"brilliant cut" citrine. |
|
CTR -
Center:
|
The weight of the center
or focal point stone in a piece of jewelry containing more than one stone.
|
|
Cabochon:
|
A cutting style that
produces a convex surface with no reflecting facets, the stone has the shape
of a dome. Used on opaque or semi-opaque stones. |
|
Calibrated:
|
A gemstone whose
dimensions are a standard (mm) size and are cut to fit ready made jewelry
findings or pieces.
|
|
Cameo:
|
A raised or bas-relief
carving on gem materials; most usually seen on shells.
|
|
Carat Weight or carat
total weight or ctw:
|
The weight used in the
gem trade since antiquity. Since 1907, Europe and America has adopted the
metric carat of 200mg or 0.2g. (Weights given to famous old diamonds often
vary because metric measure was not used). Small diamonds are weighed in
"points" =1/100cts (=0.01cts.) One full carat 100 points = 1/5
gram (or .2gr.) 3.0 carat total
weight refers to the cumulative weight or carats of all stones in the piece
of jewelry.
|
|
Cathedral
Mounting:
|
High profile ring
setting that arches when seen from the side. |
|
Chain styles |
Omega - Links in the shape of the Greek letter
Rope - twisted strands woven to resemble rope.
Snake - A metal chain
made up of a series of small linked cups with curved joints to suggest
snakeskin
Box Chain -
A chain with links resembling small
overlapping boxes. |
|
Center Gemstone Stone
Shape:
|
Baguette
- A simple, rectangular
step-cut, primarily in diamonds, sapphires, and rubies.
Bead - A drilled stone designed to be strung.
Briolette
- A tear-drop shaped stone with
facets all around. This type of stone makes a nice pendant or earrings.
Cushion
- Indicates a rectangular shape.
Emerald
- Stone cut into a rectangular
or square shape, with rectangular facets arranged in rows that look like
flights of stairs.
Heart
- A stone cut into the shape of
a heart.
Marquise
- A fancy gemstone cut; long,
and pointed at both ends.
Multi-Stone
- A piece of jewelry with
several stones grouped together creating the illusion of one large center
stone.
Oval
- An elongated circle.
Pear
- A teardrop shaped stone.
Princess
- A square cut stone or
rectangular with triangular and kite shaped facets.
Radiant
- A stone cut into a rectangular
shape with the corners clipped unlike a princess cut which has pointed
corners.
Round
- This shape gives maximum
brilliance from most diamond crystals.
Trillion
- A stone cut into a triangle.
|
|
Center Setting
Style:
|
Baguette
- A simple, rectangular cut
primarily in diamonds, sapphires and rubies.
Bar - A setting style where each
setting is held in by a bar, shared between each stone.
Basket
- A fancy setting of various
shapes with numerous side piercing that provide a basket work or a lacy
appearance.
Bezel
- A style setting in which the
girdle of the stones is completely encircled by ad set flush with the
metal.
Channel
- Low metal setting holding
gemstones on 2 sides only.
Half Bezel
- A type of setting in which the
girdle of the stones is partially encircled on two sides and set flush with
the metal.
Multi-Stone
- A piece of jewelry with
several stones grouped together creating the illusion of one large stone.
Prong
- A setting consisting of a
series of prongs or claws to hold a stone. Such settings usually consist of
4 or 6 prongs.
Tension
- Opposite ends of a setting
hold a stone by the force of tension, making it appear it is floating.
Tiffany
- This high prong setting is
most common today.
|
|
Chevron
Style:
|
A "V" shaped
design seen primarily in rings and necklaces. |
|
Chatoyancy:
|
An effect which
resembles the slit eye of a cat caused by reflection of light by parallel
fibers, needles or channels in the stone. Most effective in a cabochon cut.
Most common is of chrysoberyl.
|
|
Choker:
|
A necklace designed to
be worn up closely to the neck. Normally 16" in length or shorter,
depending on neck size. |
|
Clasp
styles:
|
Barrel Clasp
: a round or oval solid body
fastener which resembles a barrel. The two ends screw into each other.
Box clasp
: A type of bracelet or necklace
clasp in which the female end is a box and the male end is designed to fix
inside the box.
Lobster clasp
: fastener than resembles the
claws of a lobster and opens and closes in a pincer movement.
Safety clasp
: a secondary closure (usually on
a necklace or bracelet) that prevents the loss of the jewelry in case the
primary clasp opens.
Toggle
: a jewelry fastener in which a
bar can be inserted into a ring to fasten two sides of a piece of jewelry
usually the two ends of a bracelet or necklace. |
|
Cluster:
|
A group of closely set stones.
|
|
Cocktail
Ring:
|
A ring of three-dimensional
design, usually combining small diamonds with other gemstones on varying
levels for maximum reflective possibility. |
|
Color-Enhanced:
|
Any treatment process
that enhances or changes the color of a gemstone. This may include
heat-treating, irradiation, dying, bleaching, oiling, to name a few.
|
|
Comfort Fit:
|
The inside shank of a
ring that is slightly rounded (convex) to provide a more comfortable fit.
|
|
Crown:
|
The upper part of a
gemstone, between the girdle and the table.
|
|
Cubic Zirconia:
|
An inexpensive,
lab-produced gemstone that resembles a diamond.
|
|
Culet:
|
A small facet placed at
the bottom of the pavilion of a gem.
|
|
Cultured
Pearl:
|
A pearl resulting from
man inserting a bead into a mollusk, which covers it with a coating called
nacre. Almost all pearls are harvested in this manner today.
|
Diamond Grading:
Cut:
|
To grade for cut, the type, shape proportions and symmetry as well
as outer marks are considered. The grades are self-explanatory: Very
Good; Good; Medium: Poor.
The "cut" is a term used to refer to the fashioning of a
gem. Other
cuts used in all gemstones are:
Antique:
small table surrounded by symmetrical facets
Briolette:
slender pear shaped stone covered with facets.
Eight-cut:
eight facets on upper and lower parts as well as the table. Used for
diamonds too small for full cuts.
Fantasy cuts
: the popular cuts in recognizable shapes of hearts, coats of arms,
flowers, animals, etc. Rarely faceted.
Pear-shaped:
oval stones, diamond or any other gemstone cut with oval table facets above
and below girdle.
Marquise (marquis) or Navette
: Refers to as the ""marquise" shaped
stone faceted high up on the crown, leaving a small table.
Rose cut:
An antique facet cut without table or pavilion. Varies on number and
positioning of facets. Not used in last century, thus an indicator of very
antique jewelry.
Scissors cut
: A type of step cut. The facets are divided into four sub-facets by
the "scissors".
Ceylon cut:
Numerous facets, cut to obtain maximum weight and therefore is not always
symmetrical. It is usual to re-cut such stones.
Emerald cut:
Step cut with octagon shape, especially used for emerald, but also for
longer shaped diamonds.
Single cut:
a 17-facet cut used on smaller diamonds
Table cut
: The simplest type of step cut
which is very flat with a large table. It is often used for seals or rings
for men. |
Diamond
Diamond Clarity Grade:
|
"C" is the chemical symbol for diamond ---crystallized
carbon C. It has an isometric (cubic) crystal system. It is the hardest
mineral on earth, a 10 on the universal Mohs' Hardness scale, with a
specific gravity of 3.47-3.55. It rates "perfect" on cleavage
rating, important to the stonecutters. Cleavage refers to the manner in
which the stone's atoms cling together, understanding cleavage is essential
when splitting and cutting large stones.
Clarity is the term that describes the degree of freedom from
inclusions and blemishes in a diamond. Kohinoor advises that gemstones and diamonds should be viewed with a 10x
magnifier (jeweler's loupe) on a white background.
F1 (Flawless) - is the term used by the GIA
(Gemological Institute of America) clarity grade to describe a magnificent
diamond totally free of blemishes or "inclusions" under 10x magnification.
IF (Internally Flawless) - GIA
clarity Scale: A diamond with no internal characteristics at 10x
magnification, but which have minor surface blemishes that do not penetrate
the stone.
VVS1 & VVS2 (Very very slightly included) - GIA clarity grades describes
a diamond with minute inclusions that are very difficult to see under 10x
magnification.
VS1 & VS2 (Very slightly included) - GIA clarity grades describing
diamonds with minor inclusions ranging from difficult to see, to somewhat
easy to see under magnification and on a white background.
SI1 & SI2 (Slightly included) - GIA clarity grade state that
this is a diamond with inclusions that are easily recognized under 10x
magnification. Stone should be viewed on a white background. Look at the
stone from the bottom (pavilion). These inclusions may be visible to the
naked eye on a white background.
I1, I2, & I3 - GIA clarity grades assigned
when there are obvious inclusions in a diamond which may be eye-visible,
face-up.
|
|
Diamond Color Grade:
|
Believe it or not, diamonds are found in all colors. The most prized
is colorless, the dazzling white most people associate with diamonds. Most
diamonds come in white to yellow to brown. More rarely they have strong
colors- pink, green, blue, red, violet, brown, and yellow (canary). These
colored diamonds are called "fancy color diamonds" and may bring
collectors' prices. For commercial purposes, gem diamonds are graded from yellowish
to white (colorless).
Diamond color grade assesses the absence of color. Diamond color is
graded on a scale from D through Z, with D, E and F regarded as colorless.
Light Brown (LTB). These particular diamonds are found in the GIA's
n-z range and are of a brownish hue. They have been selected for their
attractive appearance and outstanding value.
Top Light Brown (TLB). These particular diamonds are found in the
GIA's k-m range and are of a brownish hue. They have been selected for
their attractive appearance and outstanding value.
See the Four Cs article under in the Education section for
more information on diamond color grade.
|
|
Diamond Council of
America (DCA):
|
An organization
certifying "Diamontologists."
|
|
Diamond
Rough:
|
A diamond still in its
natural state, before faceting or polishing.
|
|
Diamond-Cut:
|
Besides referring to a
diamond's cut (see diamond above) this term also refers to a process in
which gold is "diamond-cut" or faceted to make it
"sparkle."
|
|
Dispersion:
|
The multi-colored
flashes of light from a well cut diamond. It gives gems their internal
fire.
|
|
Doublet:
|
Two gemstones cemented
together for durability or enhanced visual appeal, such as opal and black
onyx. Doublets are created in several ways and use many combinations. Upper
and lower parts of natural gemstone have colored glue between them: or the
upper part is gemstone and the lower part is colored glass. Where the
doublet has a thin top layer of harder stone for the protection of the
surface, it becomes a triplet.
|
|
Earring Back
Design:
|
Hinged Hoops
- Hoop earrings which are hinged
usually at the bottom, to open for ease of putting on and taking off.
Lever Back
- A type of earring mounting
that allows the gemstone to dangle from the earlobes.
Omega Back
- Hinged back for hoop earrings,
in the shape of the Greek letter omega.
Screw Back
- A pierced earring post with
grooves cut into in so that the back may be screwed on.
Friction posts
- Earring base requiring applied
tension to release the back from the post
|
|
Earring
Design:
|
Chandelier
- "party" earring with
many dangling layers. Made famous of late by celebrities such as Nicole
Kidman and Jennifer Lopez.
Dangles
- Earrings that
"dangle" off the ear.
Hoops
- Earrings designed in a rounded
loop from the front to back of the earlobe.
J-Hoops
- Half hoop earrings that
resemble the letter "J"; does not completely encircle the ear
lobe
Jackets
- A piece of jewelry that fits
around another piece; earring jackets are used to "dress" a plain
workday stud. They can be almost any design and stone, i.e. pearls (and or
diamonds) to encircle a plain gold stud; a dangling piece with movement--
to go dancing after work, etc.
Stud
- A small, often round earring
made for a pierced ear.
|
|
Eye Loupe:
|
A hand-held magnifying
lens used to examine gems. Usually 10x magnification, but can be higher.
|
|
Facet:
|
A flat, polished surface
cut into a stone.
|
|
Fancy Color
Diamond:
|
See diamond Color. The
"fancy diamonds" are more highly saturated colors of the natural
stone--even browns and yellows. A diamond that falls outside the usual
color range from whites to light yellow and brown are considered
"Fancy".
|
|
Findings:
|
Pre-manufactured small
parts of jewelry such as settings, clasps, jump rings, etc...
|
|
Flaw:
|
In gem terms, an
imperfection (flaw) which is visible at 10x magnification.
|
|
Four Cs:
|
Phrase coined to
describe the 4 quality and value considerations of a diamond: cut, color,
clarity, and carat weight. Scroll down to diamond or...
For more information see our article in the Education
section about the 4Cs.
|
|
Fracture
Filling:
|
Most often used in
emeralds, which are prone to cracks, this process uses a glass-like
substance to fill and thereby strengthen the stone. It's a non-permanent
solution, but can last for generations. The best fills cannot be detected
with the naked eye.
|
|
Freshwater Cultured
Pearl:
|
These pearls are formed
in mussels living in freshwater lakes or rivers. Mantle tissue from a
mussel is inserted into the mussel rather than a shell bead. Freshwaters
are less expensive than their salt-water cousins; they are known for their
out-of-round charming shapes, and range of colors at a good price.
|
|
GIA:
|
The Gemological
Institute of America is an independent nonprofit organization renowned for
its impartial service as the world's foremost authority in gemology. They
offer nonprofit education, research and laboratory services including diamond
grading.
|
|
GIA
Inscription:
|
Since the invention of
the laser, GIA graded diamonds may have the grading report number
laser-inscribed on the stone's girdle. This number matches the GIA grading
report.
|
|
Gemstone:
|
A naturally occurring
mineral that is valuable, rare and often beautiful.
|
|
Gemstone Types: |
Alexandrite
- A very rare stone noted for its color changing abilities. Known since
pre-history, it was named for Czar Alexander II. It is chrysoberyl and
rates an 8 on the Mohs' Hardness scale. Colors are greenish outdoors, and
reddish to violet under artificial light. There are Alexandrite cat's eyes
in existence but of even greater rarity. Alexandrite is one of the
birthstones for June.
Amethyst
- A silicon dioxide --quartz gemstone, rating 7 on the Mohs' hardness
scale. Ranging in color from clear purple to bluish violet. Birthstone for
February. Legendary powers: brings luck, ensures constancy, protects
against magic.
Aquamarine -
Belongs to the beryl group, as does emerald and beryl. Mohs' hardness is 7
-8. The name translates to "water of the sea" because of the
usual color. Semi-precious porous stone ranging in color from light blue to
sea green. Increasingly rare, the "synthetic" aquamarine is
synthetic spinel, and the color is richer than many natural stones.
Birthstone for March.
Black Star Sapphire
- A cabochon cut black sapphire with a 6 ray star.
These stones are always heat treated to improve their color.
Blue Star Sapphire
Mohs' Hardness of 9. The mineral is corundum. A cabochon
cut blue sapphire displaying a 3 ray, 6 point star.
Blue Topaz
- A topaz ranging in color from pale blue to bright blue. Most blue topaz
is irradiated & heat treated to produce their blue color. Birthstone
for December.
Cats Eye
- Chatoyancy is a phenomenon seen in various gems when they are cabochon
cut, resulting in a bright single line down the center.
Ceylon Sapphire
- These deep royal blue sapphires from Sri Lanka, formally Ceylon,
are the finest in the world.
Citrine -
A semi-precious quartz gemstone, ranging in color from a light yellow to a
brilliant orange. Birthstone for November
Diamond -
(See above). A very valued gem composed of pure carbon, the hardest of all
known natural substances. Birthstone for April.
Emerald -
Belongs to the beryl group. One of the most valuable gems, ranging in color
from green to bluish-green. The green pigment is chrome, and is
incomparable in the gem world. Known for its "inclusions" which
are not necessarily known as faults, since they are evidence of the genuineness
of the stone. Experts refer to these as the emerald's "jardin"
--garden. Birthstone for May.
Garnet -
A group of semi-precious stones ranging in all colors but blue. Most
commonly a deep red. Name comes from Latin for grain, because of the
rounded shape of the crystals. Garnet is understood to mean pyrope and
almandine, 7-71/2 on the Hardness scale. Birthstone for January.
Iolite - A transparent, violet blue, light or yellow gray
mineral. Also known as the water sapphire. 7-71/2 on the Mohs' scale.
But difficult to cut.
Mother of Pearl
- The material obtained from the inside of the shell of a certain
large mollusk.
Onyx - A
quartz mineral (chalcedony) that is usually black. 61/2-7 on the Mohs'
hardness scale. Ancient talisman against depression.
Opal -
Some of the most stunning of the semi-precious stones; luminous and
iridescent, frequently with inclusions of many colors. Opals always contain
water, and over generations the stone can lose water. Store in moist
absorbent cotton to prevent this. Care must be taken with setting. Too much
heat evaporates the water. Birthstone for October.
Pearl -
Organic gems of calcium carbonate grown within mollusks-- specifically
oysters, although in very rare cases, snails have produced pearls. Although
the Moh's hardness is only 3-4, they are so compact it is very difficult to
crush one. Colors range from white, cream, golden, pink, silver green, blue
and black. The type of mollusk and the water it is in, determines the
color. Care can preserve pearls for generations. Perfume, perspiration and
hair spray are enemies of pearls. Birthstone for June.
Peridot -
Formerly called "chrysolite", it is a yellow-green semi-precious
stone. Also called olivine. 6-71/2 on the Hardness scale. In Middle Ages
used for ecclesiastical purposes. It can burst under great stress and is
usually metal foiled. Birthstone for August.
Rhodolite: A member of the garnet pyrope group 4-5 on the
Mohs'. Mistakenly called "cape ruby". Color range from rose-red
or pale violet.
Ruby - a
corundum with the Mohs' rating of 9, making it the hardest mineral after
diamond. Ruby has no cleavage but has preferred directions of parting.
Inclusions are common and not an indication of lower quality. Some rubies
when cut en cabochon give a cat's eye or the very desirable asterism-a 6
rayed star which moves over the surface when stone is moved. Color ranges
from deep red to pink and into brown hues. Corundum unsuitable for jewelry
is used as a cutting and polishing medium. Rubies are one of the most
expensive gemstones. Birthstone for the month of July.
Sapphire
- a corundum with the Mohs' rating of 9, making it almost as hard as
diamond. Today corundums in all colors except red (which are rubies) are
called sapphires. There is really no definite demarcation between ruby and
sapphire. Also found with the rutile needles making a cats' eye or
marvelous 6 rayed star when cut en cabochon. Most popular as a blue stone
and the most desired are Kashmir sapphires, although they now come from
Burma. Birthstone for September.
Spinels-
magnesium aluminum oxide with a rating of 8 on the Mohs' scale. They occur
in all colors, the favorite being a ruby-like red. Star spinels are very
rare. It was only recognized as an individual mineral 150 years ago, before
that is was thought to be ruby, because it also occurs with it. Some
well-known rubies are truly spinels.
Tanzanite
- First found in Tanzania East Africa and named for that country by Tiffany
& Co. Mineralogists refer to it as blue zoisite. 61/2 -7 on the
Hardness scale. Gorgeous color enhanced by heating. A valuable transparent
blue-purple stone and cat's eyes are also found.
Topaz -
in antiquity all yellow and brown gemstones were called topaz. The colored
topaz stones are rarely vivid in hue. Hardness is 8, but it's not without
danger of cleavage. It has a wide color range, the most valuable of which
is pink., sometimes referred to as Imperial Topaz.. Birthstone for
November.
Tourmaline
- 7-71/2 on the Mohs' scale. No
gemstone has such richness in color variation. There are several varieties:
Achroite--nearly colorless -rare; rubellite -pink to red, sometimes with a
violet tint. Dravite-yellow brown to dark brown; verdelite-green in all
shades; Indigolite-blue inall shades; Siberite-lolac to violet blue;
schorl-black, very common. Rarely used for jewelry. One color tourmalines
are rare. Most crystals have various shades. The pink to reddish color
tourmaline is one of the birthstones for October.
|
|
Girdle:
|
The widest part of a cut
gem, where the crown and pavilion facets meet. On better diamonds,
such as our AGS-certified Ideal Cut diamonds, a laser ID is placed on the
girdle. |
|
Gold Plate:
|
A base metal that is
electro-plated with gold or an alloy of gold. Also known as gold flash,
gold finish or gold tone.
|
|
Gold-Filled:
|
A layer of gold adhered
or bonded to metal. The weight of gold must be 1/20 of the total weight or
better and must be 10kt or better.
|
|
Guard Ring:
|
Ring or rings worn on
each side of a solitaire, also sometimes fastened together at the
bottom.
|
|
Hardness:
|
Refers to one mineral's
ability to scratch another ranging from 10 which is diamond, the hardest.
At the other end is talc, which can be scratched with a fingernail.
Although popular opinion says the non-professional's method of testing for
a diamond is ability to scratch glass, any mineral from a 7 through 10 can
do the same. Measured by the Mohs's scale.
|
|
Hematite:
|
Hematite, or bloodstone,
is an iron oxide. It ranges from black, black-gray, to brown red and is
bright red when cut into thin plates. It's a 5 1/2-6 1/2 on the hardness
scale and was used as mourning jewelry in earlier times. Popular for
intaglios (engravings). |
|
Heat
Treated:
|
The now common process
of heating a stone to a high temperature in order to enhance the color or
clarity.
|
|
IRE:
|
Otherwise known as an
Insurance Replacement Estimate, this is an estimate of jewelry value for
insurance replacement purposes.
|
|
Imitation:
|
Constructed to look like
the genuine article whether it be gem or metal, but lacking the crystal
structure and chemical composition.
|
|
Insert:
|
This is a trade
reference to a double ring, sometimes ornamented with gems, with a space
between to accommodate another ring in its center. Most often used as guard
rings for a valuable center gemstone ring.
|
|
Ivory: |
Originally referring
only to elephants' tusks, it is now recognized as the teeth of
hippopotamus, narwhal, sea lion, wild boar and fossilized mammoth.
Endangered species are hunted for their ivory, and the United States will
not allow importation or sales. But sea lion teeth are used for good
quality ivory carving now. Very soft, a 2-3 on the Mohs'. Calcium
phosphate in composition. |
|
Jasper:
|
Usually considered a
chalcedony. But some put it in a group by itself within the quartz group.
It is 6-7 in the Mohs'. Known for its fine grained streaking, lending
itself to special types of jewelry. There are many names and types of
jasper: agate, Egyptian, riband, basanite, blood, scenic jasper (this
latter variation is very popular now; the inclusions create a scenic
image.) Petrified material is often jasper. |
|
Lapis Lazuli:
|
Blue stone of sulphur
containing sodium aluminum silicate. 5-6 on the Mohs' scale. Composed of
several minerals. Very sensitive to high temperatures, hot baths and acids.
Usually spotted or striped. Well-distributed fine pyrite is advantageous,
increases the value. Used for jewelry in the Middle Ages, and some castles
have wall panels and columns of lapis. |
|
Loupe:
|
A small magnifying lens
used to view diamond and jewelry, usually 10x magnifications.
|
|
Mandrel:
|
Tapered, cylindrical
metal device with measurement marks used at a jewelry store to measure a
ring's size.
|
|
Melee:
|
Small stones less than
1/4 ct in weight.
|
|
Metal Color:
|
The following are the resulting colors when mixing or alloying:
Yellow Gold
- Gold that has been alloyed
with a mix of 50% copper and 50% silver.
White Gold
- Usually an alloy of yellow
gold, copper, nickel, and zinc that results in a white colored metal. Since
this is yellow gold alloyed to appear "white" it has a slightly
yellowish tint until it is plated with rhodium, which gives it a bright
white finish.
Two-Tone
- A piece of jewelry using both
white and yellow metals.
Rose Gold
- Gold that has been alloyed
with a mix of 90% copper and 10% silver producing gold with a pink tinge.
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Metal content and gold
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Combined substances are alloyed to produce a type of metal used for
jewelry.
Base Metal
- Any non-porous metal. Plated -The process of covering one metal
with another using electricity. Solid - Entirely of one metal or
containing the minimum alloy necessary to impart hardness.
Karat -
abbreviated 'kt', is a method of
measuring the amount of pure gold in an alloy. These proportions are
10, 14, 18, 22, or 24. 100% is equivalent to 24 kts -pure gold. To
calculate the amount of precious metal, divide the karat number by 24. For
example, 14 kt divided by 24 equals 58.3% gold. Gold is commonly sold as
10kt, 14kt, 18kt and 24kt. Gold is a soft metal-in its pure state it can
be scratched with a fingernail. That's why rings and other daily-wear
jewelry are generally made of 14 and 18kt gold, rather than 24kt.
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Metal Type:
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These are the common types of metal used in making jewelry:
Gold - A
shiny, bright-yellow, precious metal that is mined from the earth. This
soft metal's purity is expressed in karats, 10kt, 14kt, and 18kt being the most
common.
Overlay Vermeil
- Gold applied over a silver base.
Platinum
- A very heavy, durable metal that is usually 90% to 95% pure, alloyed with
5% to 10% of another precious metal. It is known for its distinctive
cool, white color.
Silver
(fine Silver) - .999 or 99.9% pure silver, occurring naturally in the
earth. In this form, it is too soft to be used in jewelry.
Stainless Steel
- A durable metal typically used in creating watch cases and bands.
A key element to look for when selecting water sport watches.
Sterling Silver
- A mixture of 925 parts fine silver and 75 parts copper.
Titanium
- A very strong, ultra-light metal sometimes used to create watch cases and
bands, making them some of the lightest watches available. It is
hypoallergenic and resistant to salt water corrosion.
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Mixed Cut:
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This style is a
combination of the brilliant and step facets. Many mixed cuts have step
faceting on the crown and brilliant faceting on the pavilion, however this
is sometimes reversed. The two types of facets can be combined on the
crown, pavilion or both. To learn more about the characteristics of a
diamond, go to the diamond buying guide.
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Moh's Scale:
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The usual scale of
hardness used in the jewelry industry, introduced by F. Mohs.
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Moonstone: |
A feldspar named after
the blue-white sheen inherent, which can also produce moonstone cats' eye.
6-61/2 on the hardness scale. Cut in cabochon, always.
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Mother's
Ring:
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Ring set with the
birthstone of each child or grandchild, usually a straight line, but
increasingly in cluster settings. Worn by mothers and grandmothers.
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Mounting
Design:
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Bypass shank - A ring
design in which the two sides of the band do not meet in a straight line,
but "bypass" one another. Straight - A style of mounting where
the two sides of the shank are straight across from one another at the top.
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Mounting
Finish:
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Florentine - An etched
metal finish, similar to satin but with a noticeably deeper etching in the
gold.
Polished - Most popular
finish on gold, giving it a smooth finish and a bright shine.
Satin - A widely used
finish on gold, achieved by dulling the surface to create a silk like luster
instead of a shiny surface.
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Nacre:
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A smooth hard
crystalline substance composed of microscopic crystals of calcium
carbonate. A mollusk secretes this substance and uses it to coat an irritant
that has become lodged in its soft inner body. As long as an irritant
remains in the oyster's body it will continue to secrete a layer of nacre
around it. Over time the irritant will become completely covered in nacre.
The result is a pearl.
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Natural
Pearl:
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A natural pearl results
from nature inserting an irritant into a mollusk and the mollusk secreting
a natural coating which covers it. These are very rare and nearly
impossible to find today. Most are cultured pearls, invoked by man-made
introduction into the mollusk and cultivated over time.
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Necklace Lengths and
terms :
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Princess Length - An 18" strand of pearls
Matinee Length - A 20" - 24" strand of pearls
Opera Length - 28" - 30" strand of pearls
Graduated Multiples - Several chain lengths in one necklace
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Necklace Accoutrements:
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Pendant
- A hanging ornament that may
appear on a necklace, earrings or a pin. Locket
- A pendant (heart-shaped or
otherwise) that can open up and hold a small object such as a photo. Slide
- An ornament often decorated
with diamonds or gemstones that slides upon a necklace. Solitaire
- Although usually referring to a
ring with a single stone, this refers to any piece of jewelry with one
important gemstone; it can have supporting stones on the sides. Sticks
- A style in fashion jewelry
that has long straight lines resembling sticks.
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Oil Treated:
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Treatment usually used
on emeralds to prevent numerous inclusions from detracting from the beauty
of the stone. Often used on opal to prevent cracking.
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Orient:
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A term referring to the
luster of a pearl.
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Pavilion:
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The lower part of a cut
gemstone, below the girdle.
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Pearl Shape:
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Baroque
- An irregular-shaped pearl.
Mobe
- A large one-sided cultured
pearl which has formed on the concave shell of the oyster and is flat on
one side.
Off Round
- Any pearl that is not
"round," but has a slightly irregular shape. Round
- A perfectly round pearl.
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Pearl Size:
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Seed Pearl - Very small,
very round pearls often less than 2mm in diameter.
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Plumb Gold:
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Gold that is not less
than the stamped kt. content. 14kt plumb gold means that the gold will be
at a minimum 14 parts gold mixed with 10 parts alloy. It is an assurance
that gold is not under karated.
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Point:
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Unit of weight. 1 point
is equivalent to 0.01 (1/100) carats.
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Post:
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The metal stem of a
pierced earring, increasingly in stainless steel, for nickel metal allergy
sufferers.
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Precious
Stones:
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An obsolete term which
generally is used to refer to diamond, emerald, sapphire, or ruby.
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Prong:
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A narrow piece of metal
that is folded over the girdle of a stone to secure it in a setting.
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Proportion:
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The relationship between
the diamond's angles and parts. Refers to facet angles and the relationship
between the crown (portion above the girdle) and pavilion (portion below
the girdle).
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Refractive
Index:
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A measure of how light
is bent as it enters and exits a gemstone. Each mineral has a
refractive index, and that serves as an identifier. The amount of
refraction in crystals is constant in the various types of gems. |
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Rhodium:
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A white metallic element
of the platinum group that is harder, whiter, and more reflective than
platinum. It is widely used for plating. |
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Scintillation:
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Refers to tiny flashes
of light when the diamond, the light source, or the observer moves. Most
often seen in the diamond's stunning sparkle.
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Semi-precious
Stones:
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An obsolete term used to
describe gemstones which are not diamond, emerald, sapphire, or ruby. These
terms are misleading as many "semi-precious" gemstones are
extremely valuable, and rarer than precious stones. Some
"precious" gemstones are of such poor quality that their value is
very low.
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Shank:
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The part of a ring which
encircles the finger and to which the setting for stones is attached.
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Side Setting
Styles:
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Baguette
- A simple, rectangular cut, primarily in diamonds, sapphires and rubies, used
to flank different shape central stones.
Bar - A
setting style where each stone is held in by a bar, shared between two
stones.
Bezel - A
style setting in which the girdle of the stones is completely encircled by
and set flush with the metal.
Channel -
Low metal setting holding gemstones on 2 sides only with table at about
level with the metal sides.
Multiple Stones
- A piece of jewelry with several stones grouped together creating
the illusion of one large stone.
Nick -
This setting style is designed to look like channel setting, but the stones
are actually held by small prongs "nicked" in the side of the
channel. It enhances the central diamond making it appear larger.
Pav? -
(pronounced pav-ay) Covering an entire area of metal with small stones set
very close together and secured with beads of metal. Setting an entire area
of metal
Prong - A
prong is a tiny metal arm or claw holding a stone in place. Such settings
usually consist of 4 or 6 prongs.
Tension -
Newer setting by master jewelers in which opposite ends of a setting hold a
stone by the force of tension, making it appear it is floating.
Tiffany -
A high pronged setting for an engagement ring is most common today. The
prongs should be checked by your jeweler every 6 months. |
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Solder:
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Pronounced /saw-der/, a
metal alloy used when joining two metal surfaces.
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Modern Watch Terminology
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Alarm
- A signaling device that can be
set to sound off at a certain time.
Bracelet
- Also known as the watchband,
it is part of the watch that goes around the wrist. It can be made of
leather or metal or even gemstones.
Case
- The outside shell that houses
the moving parts of a watch.
Chronograph
- A stopwatch function on a
wrist watch.
Crown
- The incised button is set
outside a watch case by which the watch is set.
Crystal
- High quality, transparent
protective covering. It's fitted tightly over the face of the watch.
Dial
- The plate or watch face marked
with numerals for indicating time.
Diver's Watch
- A water resistant watch which
may be immersed up to depth of 660 feet.
Kinetic
- A kinetic watch generates
electrical energy to power itself from the natural movement of the wearer's
arm and wrist.
Movement
- Refers to the inner workings
of a watch.
Perpetual Calendar
- A watch calendar that automatically
adjusts for the different lengths of the months and leap year.
Water Resistant
- The ability of a watch to
resist penetration by water up to certain water pressure depths. Most
watches are "water resistant," but not necessarily "water
proof."
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Synthetic:
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A manmade substitute
stone which has the same chemical, physical and optical qualities as its
naturally occurring counterpart. Synonymous with lab-created gemstones.
Many are extremely valuable. |
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Table:
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The largest facet at the
top of the crown of a gemstone. It is generally parallel to the
girdle.
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Tiger's Eye |
Formed from hawk's eye (a finely fibrous quartz aggregate), Tiger's eye has a very distinctive
chatoyancy when cut en cabochon, and a very silky luster. Mohs' hardness is
7. A favorite men's gemstone, the rich brown and yellow-gold is
unmistakable for anything else. |
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Total Gem
Weight:
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The combined carat
weight of all the diamonds or colored gems in a piece of jewelry; the main
pricing point for a piece. Abbreviated as TW.
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Ultra-sonic
Cleaner:
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This machine, standard
equipment in most fine jewelry stores, cleans jewelry with sound waves. But
it is not safe for all stones.
See our section on Jewelry Care and Cleaning on the
bottom navigation bar or under Education.
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Note: When you click on these external links below, you will bring up a window
to a third party site that is not Kohinoor Diamonds. Kohinoor Diamonds does not verify,
validate, warrant or endorse any product or information found on this site.