Zoisite with Ruby
Anyuiite-bearing Zoisite (Anyuiite-Ruby Zoisite) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Orthorhombic crystal system (Zoisite); Trigonal (Ruby); specimen is carved/polished into a hexagonal prism (obelisk)
Mineral Group
Silicates; Subgroup: Sorosilicates (Epidote group)
Chemical Formula
Ca2Al3(SiO4)(Si2O7)O(OH) with Al2O3:Cr inclusions
Formation Process
Metamorphic (regional metamorphism of magnesium-rich calcium rocks)
About This Crystal
A dense, opaque green matrix of zoisite featuring dark, purplish-red inclusions of corundum (ruby). The specimen is polished into a pointed tower shape, exhibiting a waxy to dull luster and a granular, mottled texture.
Physical Characteristics
Color: Mottled green with red/burgundy spots; Streak: White; Cleavage: Perfect (one direction); Fracture: Uneven; Specific Gravity: 3.25–3.36; Fluorescence: Rubies may glow bright red under longwave UV light.
Optical Properties
Refractive Index: 1.691–1.700; Birefringence: 0.006–0.018; Pleochroism: Strong in zoisite crystals but obscured in massive specimens; Optical Phenomena: Fluorescence in ruby inclusions.
Hardness & Durability
Origin Region
Mundarara Mine, Longido District, Arusha Region, Tanzania (primary source for this specific variety)
Hardness & Durability
Zoisite: 6.5; Ruby: 9.0 (average 6.5-7 on Mohs scale for matrix). Fairly durable but brittle; cleavage in zoisite makes it prone to splitting if struck.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaning due to inclusions. Store separately to prevent scratching softer stones or being scratched by harder ones.
Rarity & Value
Relatively common as decorative material; value is determined by the brightness of the green zoisite and the size/vibrancy of the ruby inclusions. Generally affordable.
Special Characteristics
Features a unique combination of two distinct minerals; some specimens may contain black Pargasite (hornblende) needles. The rubies often exhibit strong UV fluorescence.
Lore & History
Known as Anyolite (from the Maasai word 'anyoli' meaning green); historically discovered in the 1950s. In metaphysical lore, it is believed to balance the heart and third eye chakras, symbolizing growth and passion.