Thulite

Last updated
Thulite
Thulite.jpg
Thulite from Leksvik, Norway.
General
Category Sorosilicate variety
Formula
(repeating unit)
(Ca,Mn)2Al3(SiO4)(Si2O7)O(OH)
Crystal system Orthorhombic
Identification
ColorPink
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]

Manganese Chemical element with atomic number 25

Manganese is a chemical element with the symbol Mn and atomic number 25. It is not found as a free element in nature; it is often found in minerals in combination with iron. Manganese is a transition metal with important industrial alloy uses, particularly in stainless steels.

Mineral Element or chemical compound that is normally crystalline and that has been formed as a result of geological processes

A mineral is, broadly speaking, a solid chemical compound that occurs naturally in pure form. Minerals are most commonly associated with rocks due to the presence of minerals within rocks. These rocks may consist of one type of mineral, or may be an aggregate of two or more different types of minerals, spacially segregated into distinct phases. Compounds that occur only in living beings are usually excluded, but some minerals are often biogenic or are organic compounds in the sense of chemistry. Moreover, living beings often synthesize inorganic minerals that also occur in rocks.

Zoisite sorosilicate mineral

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

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.

Sauland Village in Eastern Norway, Norway

Sauland is a village (parish) and the administrative center in Hjartdal municipality in Telemark county. The population is above 800 people in 2016, which equates over half of all households in the whole municipality. The village is placed in the south/east corner of the municipality and is one of the three parishes in Hjartdal. The place was until Notodden was founded, a center in Aust-Telemark, and had at this time the magistrate for the district. Until 1860 it had its own separate stave church, which was torn down and replaced with the wooden church that stands today.

Telemark County in Norway

Telemark[²teːləmɑrk](listen) is a traditional region and county in Norway. The region borders Vestfold, Buskerud, Hordaland, Rogaland and Aust-Agder. Telemark means the "mark of the Thelir", the ancient North Germanic tribe that inhabited what is now known as Upper Telemark in the Migration Period and the Viking Age. Telemark will cease to be an administrative entity on 1 January 2020, when the county is set to merge with neighboring Vestfold to form the combined Telemark og Vestfold administrative region.

Norway Country in Northern Europe

Norway, officially the Kingdom of Norway, is a Nordic country in Northwestern Europe whose territory comprises of the western and northernmost portion of the Scandinavian Peninsula; the remote island of Jan Mayen and the archipelago of Svalbard are also part of the Kingdom of Norway. The Antarctic Peter I Island and the sub-Antarctic Bouvet Island are dependent territories and thus not considered part of the kingdom. Norway also lays claim to a section of Antarctica known as Queen Maud Land.

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]

Austria Federal republic in Central Europe

Austria, officially the Republic of Austria, is a country in Central Europe comprising nine federated states. Its capital, largest city and one of nine states is Vienna. Austria has an area of 83,879 km2 (32,386 sq mi), a population of nearly nine million people and a nominal GDP of $477 billion. It is bordered by the Czech Republic and Germany to the north, Hungary and Slovakia to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the west. The terrain is landlocked and highly mountainous, lying within the Alps; only 32% of the country is below 500 m (1,640 ft), and its highest point is 3,798 m (12,461 ft). The majority of the population speaks local Bavarian dialects as their native language, and German in its standard form is the country's official language. Other regional languages are Hungarian, Burgenland Croatian, and Slovene.

Mitchell County, North Carolina U.S. county in North Carolina

Mitchell County is a county located in the U.S. state of North Carolina. As of the 2010 census, the population was 15,579. Its county seat is Bakersville.

Riverside, Washington Town in Washington, United States

Riverside is a town in Okanogan County, Washington, United States. The population was 348 at the 2000 census and decreased to 280 at the 2010 census.

Related Research Articles

Hornblende A complex inosilicate series of minerals

Hornblende is a complex inosilicate series of minerals. It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole.

Anyolite

Although anyolite is advertised as a variety of the mineral zoisite from Kenya and the Arusha Region of Tanzania, anyolite is actually a metamorphic rock composed of intergrown green zoisite, black/dark green pargasite, and ruby. The term anyolite is however not an officially accepted term for a metamorphic rock. It is said to be named after the Maasai word anyoli, meaning "green." Anyolite is also referred to as ruby in zoisite or Tanganyika artstone.

Staurolite nesosilicate mineral

Staurolite is a red brown to black, mostly opaque, nesosilicate mineral with a white streak. It crystallizes in the monoclinic crystal system, has a Mohs hardness of 7 to 7.5 and the chemical formula: Fe2+2Al9O6(SiO4)4(O,OH)2. Magnesium, zinc and manganese substitute in the iron site and trivalent iron can substitute for aluminium.

Epidote epidote supergroup, sorosilicate mineral

Epidote is a calcium aluminium iron sorosilicate mineral.

Pyrolusite oxide mineral

Pyrolusite is a mineral consisting essentially of manganese dioxide (MnO2) and is important as an ore of manganese. It is a black, amorphous appearing mineral, often with a granular, fibrous or columnar structure, sometimes forming reniform crusts. It has a metallic luster, a black or bluish-black streak, and readily soils the fingers. The specific gravity is about 4.8. Its name is from the Greek for fire and to wash, in reference to its use as a way to remove tints from glass.

Tephroite olivine, nesosilicate mineral

Tephroite is the manganese endmember of the olivine group of nesosilicate minerals with the formula Mn2SiO4. A solid solution series exists between tephroite and its analogues, the group endmembers fayalite and forsterite. Divalent iron or magnesium may readily replace manganese in the olivine crystal structure.

Adamite arsenate mineral

Adamite is a zinc arsenate hydroxide mineral, Zn2AsO4OH. It is a mineral that typically occurs in the oxidized or weathered zone above zinc ore occurrences. Pure adamite is colorless, but usually it possess yellow color due to Fe compounds admixture. Tints of green also occur and are connected with copper substitutions in the mineral structure. Olivenite is a copper arsenate that is isostructural with adamite and there is considerable substitution between zinc and copper resulting in an intermediate called cuproadamite. Zincolivenite is a recently discovered mineral being an intermediate mineral with formula CuZn(AsO4)(OH). Manganese, cobalt, and nickel also substitute in the structure. An analogous zinc phosphate, tarbuttite, is known.

Cobaltite sulfide mineral

Cobaltite is a sulfide mineral composed of cobalt, arsenic, and sulfur, CoAsS. Its impurities may contains up to 10% iron and variable amounts of nickel. Structurally, it resembles pyrite (FeS2) with one of the sulfur atoms replaced by an arsenic atom.

Vesuvianite sorosilicate 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.

Gahnite spinel, oxide mineral

Gahnite, ZnAl2O4, is a rare mineral belonging to the spinel group. It forms octahedral crystals which may be green, blue, yellow, brown or grey. It often forms as an alteration product of sphalerite in altered massive sulphide deposits such as at Broken Hill, Australia. Other occurrences include Falun, Sweden where it is found in pegmatites and skarns, Charlemont, Massachusetts; Spruce Pine, North Carolina; White Picacho district, Arizona; Topsham, Maine; and Franklin, New Jersey in the United States.

Tusionite borate mineral

Tusionite is a rare colorless to transparent to translucent yellow brown trigonal borate mineral with chemical formula: MnSn(BO3)2. The mineral is composed of 18.86% manganese, 40.76% tin, 7.42% boron, and 32.96% oxygen. It is a late stage hydrothermal mineral and occurs rarely in granite pegmatites in miarolitic cavities.

Clinozoisite epidote supergroup, sorosilicate mineral

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.

Manganese(II) sulfate chemical compound

Manganese(II) sulfate usually refers to the inorganic compound with the formula MnSO4·H2O. This pale pink deliquescent solid is a commercially significant manganese(II) salt. Approximately 260 thousand tonnes of manganese(II) sulfate were produced worldwide in 2005. It is the precursor to manganese metal and many other chemical compounds. Mn-deficient soil is remediated with this salt.

Manganese(II) sulfide chemical compound

Manganese(II) sulfide is a chemical compound of manganese and sulfur. It occurs in nature as the mineral alabandite (isometric), rambergite (hexagonal), and recently found browneite.

Manganoan calcite

Manganoan calcite or manganocalcite is a variety of calcite rich in manganese, which gives the mineral a pink color. Its chemical composition is (Ca,Mn)CO3. It was first reported from the Banská Štiavnica Mining District, Slovak Republic, but is widely distributed around the world, notably in the Cave of Swords at Naica, Chihuahua, Mexico, and in Bulgaria.

Hodgkinsonite nesosilicate mineral

Hodgkinsonite is a rare zinc manganese silicate mineral Zn2MnSiO4(OH)2. It crystallizes in the monoclinic system and typically forms radiating to acicular prismatic crystals with variable color from pink, yellow-red to deep red. Hodgkinsonite was discovered in 1913 by H. H. Hodgkinson, for whom it is named in Franklin, New Jersey, and it is only found in that area.

Bustamite single chain inosilicate mineral

Bustamite is a calcium manganese inosilicate (chain silicate) and a member of the wollastonite group. Magnesium, zinc and iron are common impurities substituting for manganese. Bustamite is the high-temperature polymorph of CaMnSi2O6 and johannsenite is the low temperature polymorph. The inversion takes place at 830 °C (1,530 °F), but may be very slow.
Bustamite could be confused with light-colored rhodonite or pyroxmangite, but both these minerals are biaxial (+) whereas bustamite is biaxial (-).

Serandite inosilicate mineral

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.

References

  1. Deer, Howie and Zussman, An Introduction to the Rock Forming Minerals, Longman, 1966, p. 62, ISBN   0-582-44210-9
  2. http://www.mindat.org/min-27132.html Mindat - Clinothulite
  3. 1 2 3 Mindat with location data
  4. https://www.nrk.no/trondelag/stort-funn-av-det-rosa-mineralet-thulitt-far-norske-hobbygeologer-til-a-juble-1.14324283