Yellow Gold Necklace with Natural Twisted Briolette Blue Topaz and Diamonds

Size

Though a gemstone's weight is usually given in carats, this may not give an accurate idea of its size, because different types of stone have different densities. Therefore, a one-carat sapphire or ruby will be smaller than a one-carat emerald, though they have the same weight, because sapphires and rubies (both a form of the mineral corundum) are more dense than emeralds.

Gemstones can also be measured in dimensions (diameter, length, and width). It is important to know the dimensions to ensure that the gemstone weight will be visible and well-proportioned in the setting.

Gemstone Treatment

Gemstones are often treated to enhance color and fill cracks. Please note: if a gemstone has been treated, this information will be provided in the specifications on the stone's product detail page.

There are various accepted techniques, depending on the type of stone:

Oils and resins are frequently used to fill surface-reaching fissures in emeralds and rubies. This process is not permanent; however, if a treated ruby or emerald is subjected to high heat, the filler may leak out of the stone.

Sapphires and rubies are often heated in a kiln or furnace to enhance their color. Such heat treatment, which is considered permanent, has been used for centuries.

Lightly colored sapphires may also undergo diffusion treatment. This is done by heating a stone in the presence of coloring elements such as titanium or iron, which causes a thin layer of color to be diffused into the stone's surface. Because this color layer is so thin, a diffusion-treated sapphire should not be re-polished.

Gemstone Care

To clean gemstone jewelry, first wipe it with a soft cloth to remove any dirt. Emeralds require only the use of a soft cloth, as cleaners may damage these soft gems. Sapphires and rubies can be cleaned with either an ultrasonic cleaner or a solution of one part ammonia to six parts water, with a soft brush. Store your gemstone jewelry in a soft cloth pouch or jewelry case so it does not touch other pieces in your collection. As with all jewelry, normal wear and tear can loosen prongs and settings, so it is a good idea to have it checked by a professional jeweler who can make repairs as needed.