Ruby in Zoisite
Anyolite (Corundum var. Ruby in Zoisite) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Orthorhombic (Zoisite) and Trigonal (Ruby); granular massive habit
Mineral Group
Silicates (Sorosilicates) and Oxides
Chemical Formula
Ca2Al3(SiO4)3(OH) + Al2O3 (with Cr trace)
Formation Process
Metamorphic: Medium-grade regional metamorphism of calcium-rich rocks and pegmatitic intrusion
About This Crystal
A striking combination of emerald-green zoisite matrix containing embedded opaque red ruby crystals. The specimen shown is a tumbled stone with a waxy to vitreous luster and mottled appearance.
Physical Characteristics
Green and red-magenta color; White streak; 3.35 specific gravity; Non-fluorescent zoisite with red-fluorescing rubies under SW UV.
Optical Properties
Opaque; Refractive index 1.69-1.70 (Zoisite) and 1.76-1.77 (Ruby); Pleochroic deep green and red.
Hardness & Durability
Origin Region
Longido region of Tanzania, Africa
Hardness & Durability
6.5 to 9 Mohs (Zoisite is 6.5, Ruby is 9); moderately tough but variable at crystal boundaries.
Care & Maintenance
Clean with warm soapy water only; avoid ultrasonic cleaners and steam due to different expansion rates of the two minerals.
Rarity & Value
Common to Uncommon; Value determined by the vibrancy of green and the amount of visible red ruby.
Special Characteristics
Features a unique contrast of silicate and oxide minerals; rubies often exhibit a hexagonal habit within the green matrix.
Lore & History
Discovered in 1954 in Tanzania; traditionally associated with the Heart and Base chakras, symbolizing vitality and growth.