Thulite

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Thulite
Thulite from Leksvik, Norway.
General
Category	Mineral Variety
Chemical formula	(Ca₂Al₃(SiO₄)(Si₂O₇)O(OH)
Identification
Color	Pink
Crystal habit	Massive
Crystal system	Orthorhombic
Cleavage	Perfect {010} imperfect {100}
Fracture	Uneven to conchoidal
Mohs Scale hardness	6.5
Luster	Vitreous, pearly on cleavage surfaces
Refractive index	1.69-1.70
Optical Properties	biaxial positive
Birefringence	0.006-0.018
Pleochroism	Present, dichroism or trichroism depending on color.
Streak	White or colorless
Specific gravity	3.10-3.38

Thulite (sometimes called rosaline) is an opaque, massive pink manganese rich variety of the mineral zoisite. Thulite is often mottled with white calcite and occurs as veins and fracture fillings transecting many types of rock. In mineralogical literature, thulite may sometimes refer to any pink zoisite.

Thulite was first discovered in Lom, Norway in 1820. It is named after the mythical island of Thule in the belief that the island is Norway. Thulite is used as a gemstone and carving material in the manufacture of jewelery and ornamental objects.

Thulite is also found in the Austrian Tyrol, in Mitchell County, North Carolina, and in Western Australia. A new, more recent find of high quality thulite was discovered near Riverside in Okanogan County, Washington, USA.