citrine

Scratch testing can help determine the Mohs hardness value of a mineral sample. If done carefully, this procedure can help gemologists identify…

Although gemstone magnetism isn’t a commonly tested gemstone property, it may be useful for making quick separations outside the lab. By Richard…

We tend to take light for granted. It’s such a common thing we experience every day. Rarely do we think of the scientific definition of light…

Ouro Verde quartz, also known as lemon quartz, is a popular treated stone. Learn how experiments with other gems led to the development of this treatment.…

Gemstone heat treatments can increase the beauty and value of many rough pieces. Learn how to conduct the most common procedures safely.

How can gem buyers avoid undisclosed gem treatments and substitutions? Learn why it’s best to deal with expert gem cutters rather than commercial…

Have you fallen in love with garnets? This versatile gemstone is a favorite among jewelers and gemologists, with a range of colors that few gems…

Rarely does a gemstone have popular associations with multiple colors. Traditionally, topaz was favored as a golden yellow stone. Nowadays,…

Topaz makes an excellent jewelry stone. It comes in a wide range of colors — and prices — to complement any outfit and style. Our topaz buying…