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Thulite from Leksvik, Norway.
Category Sorosilicate variety
(repeating unit)
Crystal system Orthorhombic
Crystal habit Massive
Cleavage Perfect {010} imperfect {100}
Fracture Uneven to conchoidal
Mohs scale hardness6.5
Luster Vitreous, pearly on cleavage surfaces
Streak White or colorless
Specific gravity 3.10–3.38
Optical propertiesbiaxial positive
Refractive index 1.69–1.70
Birefringence 0.006–0.018
Pleochroism Present, dichroism or trichroism depending on color.

Thulite (sometimes called rosaline) is a translucent, crystalline or massive pink manganese-bearing variety of the mineral zoisite. Manganese substitutes for calcium in the structure with up to two percent Mn2+. [1] 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. Clinothulite is the manganese bearing variety of monoclinic clinozoisite. [2]

Thulite was first discovered at a place called Sauland in Telemark, Norway in 1820. [3] It is named after the mythical island of Thule in the belief that the island is Scandinavia. [3] Thulite is used as a gemstone and carving material in the manufacture of jewelry and ornamental objects.

Thulite is also found in the Austrian Tyrol and in Mitchell County, North Carolina. A new, more recent find of a small quantity of thulite was discovered near Riverside in Okanogan County, Washington, US [3] and in Snillfjord i Trøndelag, Norway during tunnel constructions in December 2018. [4] Thulite is also found in New Zealand in the Otago region of the South Island.

Thulite is also found in Namibia. The occurrence is spread throughout the Namib Desert and generally has ridges with a NE to SW setting. The color can be highly variable with most deposits being greenish in nature, but on occasion the desirable pink color is to be found.[ citation needed ]

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<span class="mw-page-title-main">Hornblende</span> Complex inosilicate series of minerals

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<span class="mw-page-title-main">Rhodochrosite</span> Mineral of manganese carbonate

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<span class="mw-page-title-main">Serpentine subgroup</span> Group of phyllosilicate minerals

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<span class="mw-page-title-main">Zoisite</span> Sorosilicate mineral

Zoisite, first known as saualpite, after its type locality, is a calcium aluminum hydroxy sorosilicate belonging to the epidote group of minerals. Its chemical formula is Ca2Al3(SiO4)(Si2O7)O(OH).

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<span class="mw-page-title-main">Smithsonite</span> Mineral of zinc carbonate

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<span class="mw-page-title-main">Vesuvianite</span> Silicate mineral

Vesuvianite, also known as idocrase, is a green, brown, yellow, or blue silicate mineral. Vesuvianite occurs as tetragonal crystals in skarn deposits and limestones that have been subjected to contact metamorphism. It was first discovered within included blocks or adjacent to lavas on Mount Vesuvius, hence its name. Attractive-looking crystals are sometimes cut as gemstones. Localities which have yielded fine crystallized specimens include Mount Vesuvius and the Ala Valley near Turin, Piedmont.

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Larimar is the tradename for a rare blue variety of the silicate mineral pectolite found only in the Dominican Republic, around the city of Barahona. Its coloration varies from bluish white, light-blue, light-green, green-blue, turquoise blue, turquoise green, turquoise blue-green, deep green, dark green, to deep blue, dark blue and purple, violet and indigo and the larimar can come in many varieties and color mixes.

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Clinozoisite is a complex calcium aluminium sorosilicate mineral with formula: Ca2Al3(Si2O7)(SiO4)O(OH). It forms a continuous solid solution series with epidote by substitution of iron(III) in the aluminium (m3 site) and is also called aluminium epidote.

<span class="mw-page-title-main">Sauland</span> Village in Hjartdal, Norway

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Serandite is a mineral with formula Na(Mn2+,Ca)2Si3O8(OH). The mineral was discovered in Guinea in 1931 and named for J. M. Sérand. Serandite is generally red, brown, black or colorless. The correct name lacks an accent.

<span class="mw-page-title-main">Caryopilite</span> Phyllosilicate mineral

Caryopilite (synonymous with ectropite and ektropite) is a brown-colored mineral with formula (Mn2+,Mg)3Si2O5(OH)4. The mineral was discovered in 1889 from a mine in Sweden. It was named for the Greek words for walnut and felt in reference to its appearance.

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  1. Deer, Howie and Zussman, An Introduction to the Rock Forming Minerals, Longman, 1966, p. 62, ISBN   0-582-44210-9
  2. Mindat – Clinothulite
  3. 1 2 3 Mindat with location data
  4. "Uventet funn av rosa stein får hobbygeologer til å juble". 9 December 2018.