ANDRADITE VAR. DEMANTOID

ABOUT THE SPECIMEN

Beautiful green demantoid garnets are scattered all along a large piece of skarn matrix, with smaller orange garnets visible along the sides. Though a few of the demantoids are slightly dinged, many more are in perfect condition, and all of them add together to make the whole piece pop out.

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Belqeys Mountain sits 34 km northeast of Takab in the Tabak complex of northwestern Iran, where demantoid crystallized within a metamorphic horizon - mica schists interlayered with quartzites and marble intruded by granite and quartz porphyry, underlain by a 50–100 meter thick zone of metamorphosed ophiolite including serpentinite schist and metabasalt. Chegeni et al. (2021) confirmed this skarn-to-metamorphic hybrid setting distinguishes Belqeys from the purely serpentinite-hosted Russian Ural type, with chromium sourced from the underlying ophiolitic sequence driving the green color through substitution into the iron-dominant andradite structure. Crystals occur as dodecahedra to dodecahedron-trapezohedron combinations, typically deep forest-green to bright emerald, with individuals documented to 5 cm - unusually large for the species globally. Unlike Ural demantoids, Belqeys material rarely contains the diagnostic horsetail inclusions, which are characteristic of serpentinite rather than skarn genesis. The locality premiered at Tucson 2014 following initial documentation by Hairapetian in 2013, and a 2016 find produced some of the largest single crystals on matrix documented from the deposit.