Zoisite

First known as saualpite, is a calcium aluminium hydroxy sorosilicate belonging to the epidote group of minerals.
Ocures as prismatic, orthorhombic crystals or in massive forms in metamorphic and pegmatic rock.
May be blue to violet, green, brown, yellow, gray or colorless.
Blue crystals are known as Tanzanite.
Has a vitreous luster and conchoidal to uneven fracture.
Ruby can be found in Zoisite.

Characteristics:
Category sorosilicate - epidote group
Formula Ca2Al3(SiO4)(Si2O7)O(OH)
40,1% SiO2; 31,9% Al2O3; 0,1% Mn2O3; 2,7% Fe2,O3; 23,3% CaO; 1,9% H2O
Crystal system orthorhombic
Color: white, gray, greenish brown, greenish gray, pink, blue, purple
HAbit prismatic with striations, massive to columnar
Fracture uneven to conchoidal
Cleavage perfect, imperfect
Hardness: 6 to 7 Mohs
Luster vitreous, pearly on clavage surfaces
Streak white or colorless
Transparent to translucent
Speciic gravity 3,10-3,36
Density 3,15-3,36
Optical properties biaxial (+)
Luminescence:
Fluorescence orange yellow in long wave UV
Activators: main Vanadiu V
Other: Eu, Dy, Tb, Mn, V
Peak: Eu 440 nm; Dy 480,575, 578 nm; Tb 544 nm; V 700, 705, 718, 726 nm

Common associates: Ruby; Pargasite; Calcite; Actinolite; Quartz; Adularia; Prehnite; Corundum; Tschermakite; Diopsite

Other names: zoisit zoisitul zoisite