On the Mohs Scale, which measures the hardness of minerals, simulated diamonds are an 8.0 to 8.5. Ruby, sapphire and diamond are all harder substances, but simulated stones are still very durable. It is important to understand that hardness is not necessarily related to durability. Even though diamond is the hardest mineral (10.0 on the Mohs Scale), it can still be chipped or broken.

The only ways to tell the difference between simulated diamonds and diamonds are by use of a thermal probe, by weighing the loose stone or by microscopic examination of surface features and inclusions. Simulated diamonds weigh approximately 65% more than diamonds. Therefore, while a 6.25 mm round diamond weighs about 1.00 carat, the same size simulated diamond weighs about 1.65 carats. If you know the weight of a simulated diamond, you can figure out the diamond weight equivalent by multiplying its weight by 0.6, or 60%.

Glossary

Brilliance: The white light leaving a jewel, traveling upward, which is visible to the eye. Brilliance is sometimes referred to as “sparkle.”

Dispersion: Flashes of rainbow colors. Also called “fire.”

Hardness: Resistance to scratching. The higher the number, the more resistant.

Luster: The shininess of a jewel.

Toughness: Resistance to breakage.

Citrine:

Named from the French word for lemon, “citron,” citrine is a variety of quartz available in a range of golden hues from lemon, to straw, to sun yellow, to deep gold, to orange, brown and deep red. Darker colors are more highly valued, including the medium golden-orange and dark-sherry colors, sometimes called Madeira citrines after the color of the wine.

Citrine crystals can form together with amethyst to form ametrine, or with smoky quartz to form bicolored quartz. Citrine is generally less expensive than amethyst, and is also available in a wide range of calibrated sizes and shapes, including very large sizes. Considered an alternative to topaz as the birthstone for November, it is also thought to be the traditional gift for couples celebrating their 13th and 17th wedding anniversaries. Citrine ranks a 7.0 on the Mohs Scale, and because of this durability, it is ideal for jewelry wear.

Almost all citrine on the market is heat-treated amethyst, and generally starts life as either smoky quartz or amethyst geodes. Heat treatments first turn them clear and then give them a permanent color ranging from yellow to brownish-red. In some amethyst deposits, the amethyst has been partially or fully changed to brown citrine by natural means of heating, thereby transforming it into citrine. Natural citrine is pale yellow to orange, and occurs in much lighter hues than the heat-treated material. Citrines whose colors have been produced by artificial means tend to have much more of an orange or reddish caste than those found in nature. Since most citrine was originally amethyst that was heated to turn its color to gold, both citrine and amethyst jewelry should be kept away from prolonged exposure to strong light or heat.

Most citrine is mined in Brazil, but almost all of the Brazilian material is heat-treated amethyst. Supplies are most plentiful in the Brazilian state of Rio Grande do Sul, particularly from the Serra Mine. The Ira' Mine also produces large quantities of the gem. Citrine can also be found in the Ural Mountains of Russia, in Dauphine, France, and in Madagascar.

In ancient times, citrine was carried as a protection against snake venom and evil thoughts. It was thought to give calmness and mental balance to its wearer. Throughout history, people have confused citrine for topaz. Many citrines were sold as topaz and thus thought to carry the same qualities, such as knowledge and beauty. Today, citrine symbolizes truth and integrity, and is believed to promote creativity and personal clarity.