Unakite
Epidotized Granite · Semi-Precious Gemstone / Decorative Stone
Crystal System
Monoclinic (Epidote/Orthoclase) and Trigonal (Quartz). Habit is typically massive or granular in this rock form.
Mineral Group
Silicates; specifically a combination of Tectosilicates (Quartz/Feldspar) and Sorosilicates (Epidote).
Chemical Formula
KAlSi3O8 (Orthoclase) + Ca2(Al,Fe)3(SiO4)3(OH) (Epidote) + SiO2 (Quartz)
Formation Process
Metamorphic; specifically hydrothermal alteration of granite where plagioclase feldspar is replaced by epidote, while orthoclase and quartz remain.
About This Crystal
An opaque, mottled rock appearing as a heart-shaped cabochon. It exhibits a distinctive 'pistachio' leafy green color (epidote) mixed with salmon-pink to brick-red patches (orthoclase). It features a vitreous to dull luster and a granular, non-uniform texture.
Physical Characteristics
Color: Pink and Green mottled; Streak: White; Cleavage: None (as a rock); Fracture: Uneven to splintery; Specific Gravity: 2.85–3.20; Fluorescence: None to weak.
Optical Properties
Opaque; Refractive Index: Variable (approx. 1.52–1.76 depending on mineral balance); Biaxially refractive minerals within an aggregate mass; No specific phenomena like chatoyancy.
Hardness & Durability
Origin Region
Notably the Unaka Mountains of North Carolina/Tennessee, USA; also found in South Africa, Sierra Leone, Brazil, and China.
Hardness & Durability
Mohs hardness 6 to 7. Generally tough and durable for jewelry, though softer patches of feldspar may wear faster than quartz areas.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid ultrasonic cleaners and harsh chemicals, as the different mineral expansion rates may cause internal stress.
Rarity & Value
Common; very affordable. Value is based on the balance of colors (even ratios of pink/green are preferred) and quality of the polish.
Special Characteristics
Known for its unique bi-color mottled appearance; lacks specific optical phenomena like asterism but is prized for its high-contrast aesthetic.
Lore & History
Named after the Unaka Range in the US where it was first discovered. In metaphysical traditions, it is considered a stone of vision and balance, associated with the Heart Chakra to harmonize emotions and promote grounding.