No singular identifying characteristics. Use a combination of properties. Spectral Data
Not diagonistic. Trade Names and Misnomers
Rosaline
Thulite
Unionite ]]> http://www.all-gemstones.com/thulite/feed 0 http://www.all-gemstones.com/zoisite http://www.all-gemstones.com/zoisite#comments Tue, 04 Aug 2009 06:36:33 +0000 admin http://www.all-gemstones.com/?p=1545   Refractive Index : 1.700-1.695 Optical Characteristic : DR, Biaxial positive, AGG Specific Gravity : 3.35 (+.10 -.25) Formula : Ca2AI3(SiO4)3(OH)  Crystal System : Orthorhombic Variety/Species :

Tanzanite – Transparent blue to violet to bluish purple

Thulite – Translucent to opaque pink, often molted or streaked with gray or white, also called rosaline and uniolite

Ruby in Zoisite – Translucent to opaque rock like ornamental material with ruby crystals in green zoisite Species/Group : Epidote Group Birefringence : .008 to .013 Dispersion : .021 Hardness : 6 to 7 Toughness : Fair to poor Ultrasonic : Uaually safe Steam : Usually safe UV Long : Inert UV Short : Inert Pleochroism : 3 Colors Strength : Weak to strong

Brown – Strong green, purple and light blue

Yellowish green – Strong dark blue, yellow green and purple. Heat : Fusible Acids : Attacked by acids and/or chemicals Light : Stable Polish Luster : Vitreous Fracture : Conchoidal to uneven Fracture Luster : Vitreocs to dull Clarity Type : N/A Tones : N/A Saturations : N/A Cause of Color : Blue - Vanadium, Green – Chromium, Pink – Manganese Enhancements : None Cleavage : Perfect 1 direction Color Range : Brown, yellowish green, brownish, greenish Pink, often with gray or white mottling or streaking(Thulite)Blue, violet, bluish purple (tanzanite) Transparency : Transparent to Opague Phenomena : Chatoyancy (rare)