Quartz Gems (var. citrine)
|Quartz (var. citrine)||NMNH G2269||Brazil||38.88 ct|
|Quartz (var. citrine)||NMNH G3732||Brazil||277.90 ct|
|Quartz (var. citrine)||NMNH G7721||Brazil, Minas Gerais||636.60 ct|
|Quartz (var. citrine)||NMNH G3640||Brazil, Minas Gerais||781.00 ct|
|Quartz (var. citrine)||NMNH G2041||Brazil, Minas Gerais||264.75 ct|
|Quartz (var. vertrine)||NMNH G9015||Brazil||59.80 ct|
Quartz is one of the most abundant minerals in the Earth’s crust. It is the major constituent of beach sand and an important component of many types of rocks. Quartz is composed of the elements silicon and oxygen and in its pure state is colorless, but just small amounts of various impurity atoms can yield a range of vivid colors. The profusion of colors, patterns, and textures displayed by quartz is unmatched by any other mineral and makes it one of the most widely used gem materials. The Greeks referred to quartz as krystallos, meaning “ice,” and this name is the origin of the word crystal. Citrine, amethyst, rock crystal, smoky quartz and rose quartz are some of the most common varieties of quartz. Citrine is the golden yellow to orange gem variety of quartz. And like amethyst, citrine is colored by impurities of iron. The name comes from the French citron, meaning “lemon,” in reference to its color. The National Gem Collection has an extensive exhibit of quartz, including a range of citrine gems, on display at the National Museum of Natural History.