metamorphic
Ruby-in-zoisite (anyolite), polished cabochon
Corundum (ruby, Al₂O₃) in zoisite (Ca₂Al₃(SiO₄)₃(OH)); commonly with green zoisite and black hornblende
AI-generated identification · may be incorrectThe image shows a polished oval with vivid green matrix and a purple-red corundum patch, strongly consistent with ruby zoisite. Zoisite has Mohs hardness 6–7; ruby is 9, with vitreous luster and generally massive, non-cleavable appearance. Exact identification requires hardness, density, and magnified examination.
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Physical properties
The image shows a polished oval with vivid green matrix and a purple-red corundum patch, strongly consistent with ruby zoisite. Zoisite has Mohs hardness 6–7; ruby is 9, with vitreous luster and generally massive, non-cleavable appearance. Exact identification requires hardness, density, and magnified examination.
Formation & geological history
Forms when aluminum-rich metamorphic rocks undergo regional metamorphism and metasomatism, allowing ruby crystals to grow within zoisite. Classic material is Neoproterozoic–Paleozoic in age from Longido, Tanzania; the specimen’s exact locality cannot be determined visually.
Uses & applications
Primarily used for cabochons, beads, carvings, and decorative objects; translucent ruby zones may add value, though most material is ornamental rather than fine ruby gemstone.
Geological facts
The trade name “anyolite” refers especially to green zoisite containing ruby and black amphibole. Purple areas can sometimes be altered or dyed material, so color alone is not diagnostic.
Field identification & locations
Look for natural green zoisite, ruby-red to purple inclusions, and occasional black amphibole; it is notably softer than jade and scratches glass only inconsistently. The reported Sabah-region location is geologically plausible for metamorphic rocks, but this polished piece cannot be tied to that locality.
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