BY STEVE VOYNICK
Garnet mining is booming and not because of demand for gemstones or mineral specimens. Garnet has become a bona fide industrial commodity because it is a nearly perfect industrial abrasive. In just the past 15 years, annual world mine production has quadrupled to 1.2 million metric tons of refined garnet concentrate worth $340 million dollars.
The word “garnet” refers to a group of complex silicate minerals with similar crystalline structures but diverse chemical compositions. Garnet’s general chemical formula is A3B2(SiO4)3, with “A” representing such divalent metallic ions as calcium, magnesium, ferrous iron, and manganese, and “B” representing trivalent ions like aluminum, chromium, ferric iron, and manganese. In certain rare garnets, the “B” cation can also include vanadium, titanium, ort zirconium ions.