2.06 ct SCHEELITE – CHINA

Scheelite Scheelite is a gemstone that holds a brilliant secret. While it may appear as a modest, honey-colored or colorless crystal under normal light, it transforms into a glowing, neon-blue masterpiece when exposed to short-wave ultraviolet light. It is a calcium tungstate and a primary ore of tungsten, possessing a remarkable "heaviness" that always surprises those who handle it for the first time. I have always been drawn to its high refractive index and incredible dispersion, which—much like Sphalerite—allows it to show a "fire" that can rival a diamond. Faceting Scheelite is a true test of a lapidary’s skill; it is relatively soft and has distinct cleavage, but the reward is a gemstone with an adamantine luster that seems to trap and amplify every ray of light that enters it. The Heritage & Discovery Historical Significance: Scheelite is historically significant as the mineral from which the element tungsten was first identified. Before it was known as Scheelite, miners called it "tungsten" (Swedish for "heavy stone"), a name that eventually stuck to the element itself. Historically, it has been an essential industrial mineral for producing high-strength steel and filaments. In the world of rare gems, it represents the perfect marriage of industrial utility and high-end optical beauty, prized by collectors for its rare combination of high density and diamond-like luster. Discovery: The mineral was named in 1821 in honor of the Swedish chemist Carl Wilhelm Scheele. In 1781, Scheele proved that this mineral contained a previously unknown acid (tungstic acid), which led to the eventual discovery of the metal tungsten. His work transformed Scheelite from an obscure "heavy stone" into a vital resource for modern technology and a celebrated species in the world of mineralogy. Important Mines: Some of the most spectacular gem-quality Scheelite crystals come from the Mt. Xuebaoding area in Sichuan, China, famous for its sharp, orange-to-honey colored crystals on a contrasting matrix. Historically, the Morro Velho Mine in Brazil and the King Island mine in Australia have produced world-class specimens. I also have a deep respect for the classic European material from the Zinnwald region in the Erzgebirge. For our vault, I prioritize the Sichuan specimens because their structural perfection and saturated colors provide the best material for creating high-dispersion, faceted masterpieces. Mineralogical Profile Description: Scheelite is a calcium tungstate that crystallizes in the tetragonal system. It sits at a 4.5 to 5 on the Mohs scale, making it a delicate stone that is best suited for high-end display or protected collector's jewelry. It is characterized by its vitreous to adamantine luster and its range of colors from colorless and white to golden-yellow, orange, and brown. One of its most defining characteristics is its intense fluorescence—nearly all Scheelite glows bright bluish-white under short-wave UV light. It is an exceptionally dense mineral ($6.1$ g/cm³), giving even a small faceted stone a substantial "heft." Because of its high refractive index ($n \approx 1.92$ to $1.93$), it possesses a brilliance and "life" that few other colored stones can match. Chemical Formula: CaWO₄