metamorphic
Unakite
Epidotized Granite
Hardness: 6.0-7.0 (Mohs scale); Color: Mottled green (epidote), pink (orthoclase), and colorless/grey (quartz); Luster: Vitreous to dull; Crystal structure: Monoclinic/Triclinic mixture; Cleavage: None/Indistinct; Specific gravity: 2.85-3.20.
- Hardness
- 6
- Luster
- Vitreous to dull
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.0-7.0 (Mohs scale); Color: Mottled green (epidote), pink (orthoclase), and colorless/grey (quartz); Luster: Vitreous to dull; Crystal structure: Monoclinic/Triclinic mixture; Cleavage: None/Indistinct; Specific gravity: 2.85-3.20.
Formation & geological history
Formed through the hydrothermal metamorphism of granite, where plagioclase feldspar is replaced by epidote. Usually associated with metasomatic processes in deep continental crust.
Uses & applications
Commonly used for lapidary work including beads, cabochons, and small carvings. It is also used as an architectural stone for countertops and floor tiles.
Geological facts
Unakite was first discovered in the Unaka Range of North Carolina, USA. It is unique because it combines three distinct minerals into a single, cohesive rock with a striking color contrast.
Field identification & locations
Identify in the field by its distinct 'pistachio and ham' color combination. It is frequently found as river pebbles in areas with metamorphic basement rock, particularly in the Appalachian Mountains and the Great Lakes region.
More like this
