Jewelry Education


Table of Contents


Certified Diamonds

Many discerning jewelry buyers are interested in purchasing a certified gemstone. Therefore, Kohinoor Diamonds offers certain diamonds in our stores and on our website that have been certified. This means they have been inspected by an independent organization that will provide written documentation about the quality of the diamond depending on the cut, clarity, and color and carat weight.

These reports are unique to each diamond and include a diagram that will designate any natural occurrences associated with the diamond. Often, an ID number matching that of the diamond’s certificate is laser inscribed on the girdle of the stone, providing an extra measure of security and value to the buyer.

There are several organizations that provide certification, and the reports from these various organizations will vary. One of the better known of these organizations is Gemological Institute of America’s Gem Trade Laboratory. Referred to as GIA, this non- profit organization is also responsible for education and research for the diamond industry. The diamonds from Kohinoor Diamonds will have certifications from this institute as well as others in the industry.

Jewelry Care and Cleaning

Most gemstones are fairly durable; however, some require special attention. A general rule of thumb: Take off any jewelry when working in the kitchen, garden, or cleaning.

General Jewelry Care

  • Keep your fine jewelry items from contact with one another to avoid abrasion.
  • Keep your jewelry looking new by cleaning it regularly. Soap and oils from fingerprints can significantly detract from the beauty of your diamonds and fine jewelry.
  • Apply makeup and cosmetics prior to putting on your jewelry. Chemicals in these substances can often harm the look of your gold and damage pearls.
  • Avoid wearing jewelry in swimming pools. Chlorine can react with metals causing color and structural damage.
  • Fine jewelry items should not be worn while engaged in activities where they would be subject to any form of brushing or hard contact. A strong blow from the side could dislodge a gemstone from its mounting. If you decide to wear your jewelry while gardening, please exercise caution.
  • Cultured pearl necklaces should be strung with knots between each bead. Please keep all pearls away from hairspray, perfume, and cosmetics.
  • It is recommended that all jewelry be inspected semi-annually or after any sharp blow to stones or mounting. (Use our store locator for inspection sites)

Jewelry Cleaning

Cleaning your jewelry is the most important step in keeping your fine jewels as bright as the day you received them!

Ultrasonic Cleaning

Diamond, Ruby, Sapphire, Amethyst, Citrine, and Created Gemstones – Ultrasonic cleaning machines are perfect for these gemstones. Please be sure to keep items from touching one another while cleaning. Check all stones after cleaning for a tight fit in the mounting. If you do not have a cleaning machine, commercial jewelry cleaner solution or water mixed with a small amount of dish washing soap works fine with a soft cloth or brush to remove any fingerprints. Gemstones that are not translucent, such as pearls, opals or onyx, should, as a general rule, not be cleaned in an ultrasonic cleaner or cleaned with an abrasive or ammonia based cleaner.

Specific Gemstone Care

Amethyst, like its cousin, Citrine, is an extremely durable stone that will withstand normal cleaning, but avoid direct heat.
Do not use an ultra-sonic machine; avoid heat as it may cause discoloration.
Care should be taken when cleaning a topaz of any color. Do not use an ultrasonic machine. Avoid prolonged exposure to light and heat, as well as sharp blows or sudden temperature changes.
As quartz, citrine is able to withstand normal cleaning but avoid direct heat.
Because emeralds are oiled and usually included to some degree, this stone should not be placed in an ultrasonic cleaner. Emeralds should be cleaned gently with a small brush and lukewarm water. Avoid sudden temperature changes and sharp blows.
Garnet is an extremely durable stone and therefore will withstand normal cleaning.
Opal is a soft stone that requires care when cleaning. It should not be placed in the ultrasonic cleaner, nor should you use ammonia based cleaner on the stone. Clean with a soft cloth or occasionally a combination of a mild non-detergent soap (such as Woolite®) and warm water with a soft brush.
After each wearing, clean with a soft cloth. Periodically clean with very mild non-detergent soap (Woolite®); lay pearls on a clean towel and dry completely before wear. Never use ultrasonic or steam cleaners. Use only commercial jewelry cleaners that are made specifically for pearls. Avoid contact with perfumes, cosmetics and household cleaners, and return your strand to your jeweler for periodic professional cleaning and restringing.
Do not use an ultra-sonic machine. Avoid sharp blows and sudden temperature changes.
Rubies are fairly durable stones; however, the filling process often used on rubies requires special care when cleaning the stones. This enhancement technique may wear over time if treated harshly or exposed to strong solvents or abrasives. Avoid direct heat.
Because the heat treating process used is permanent, sapphires are an unusually durable stones. Normal care in cleaning is used, but avoid direct heat.
Clean with mild soap and water; do not use an ultrasonic machine. Avoid sudden temperature changes and sharp blows.

For more information on jewelry care and cleaning, visit the following jewelry industry sites:

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 third party site.

Statement of Value

Statements of Value for insurance registration purposes can be done on items purchased from Kohinoor Diamonds. You will need your receipt from the original purchase in order for us to complete the Statement of Value for you. These Statements of Value will normally satisfy insurance company requirements for insurance riders to be added to homeowner’s policies.

Industry Jewelry Buying Guide Links

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.