metamorphic
Unakite
Unakite, an epidote-altered granite composed mainly of epidote, pink orthoclase feldspar, and quartz
AI-generated identification · may be incorrectCoarse-grained, mottled green and salmon-pink rock; constituent minerals are about Mohs 6–7, with vitreous to dull luster and no consistent cleavage at the rock scale. The image’s colors and texture are consistent with unakite, though a photograph cannot confirm the identification.
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Physical properties
Coarse-grained, mottled green and salmon-pink rock; constituent minerals are about Mohs 6–7, with vitreous to dull luster and no consistent cleavage at the rock scale. The image’s colors and texture are consistent with unakite, though a photograph cannot confirm the identification.
Formation & geological history
Forms when granite undergoes hydrothermal alteration, converting much of its plagioclase feldspar to green epidote while pink potassium feldspar and quartz remain. The process is commonly associated with ancient mountain-building; the source rock may be hundreds of millions to over a billion years old.
Uses & applications
Used for beads, cabochons, carvings, decorative stone, and polished specimens; rarely used as a building stone.
Geological facts
Named after North Carolina’s Unaka Range, where it was first described; it is often sold as a lapidary stone.
Field identification & locations
Look for the characteristic intergrowth of green epidote and salmon-pink feldspar, often with quartz. It occurs in altered granites and glacial deposits, notably in the eastern United States; the pictured rough specimen has modest collector value.
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