Lazurite

Lazurite

Infobox mineral
name = Lazurite
category =
boxwidth =
boxbgcolor =


imagesize =
caption = A lazurite specimen
formula = tectosilicate (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2
molweight =
color = Deep blue to greenish blue
habit =
system = Isometric
twinning =
cleavage =
fracture =
mohs = 5-5.5
luster = translucent
refractive = 1.5
opticalprop =
birefringence =
pleochroism =
streak =
gravity = 2.4
density =
melt =
fusibility = 3.5
diagnostic =
solubility = Soluble in HCl
diaphaneity =
other =

Lazurite is a tectosilicate mineral with sulfate, sulfur and chloride with formula: (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2. It is a feldspathoid and a member of the sodalite group. Lazurite crystallizes in the isometric system although well formed crystals are rare. It is usually massive and forms the bulk of the gemstone lapis lazuli.

Lazurite is a deep blue to greenish blue. It has a Mohs hardness of 5 to 5.5 and a specific gravity of 2.4. It is translucent with a refractive index of 1.50. It is fusible at 3.5 and soluble in HCl. It commonly contains or is associated with grains of pyrite.

Lazurite is a product of contact metamorphism of limestone and typically is associated with calcite, pyroxenes, and pyrite.

Other blue minerals such as the carbonate azurite and the phosphate lazulite may be confused with lazurite, but are easily distinguished with careful examination. Lazurite at one time was used as a synonym for azurite.

Lazurite has been mined for over 6,000 years in the lapis lazuli district of Badakhshan, Afghanistan. It has been used as a pigment in painting and cloth dyeing since at least the sixth or seventh century AD (Eastaugh 2004, p. 219). It is also mined at Lake Baikal in Siberia; Mount Vesuvius; Burma; Canada; and the United States (Eastaugh 2004, p. 219). The name is from the Persian "lazward" for blue.

References

* Hurlbut, Cornelius S.; Klein, Cornelis, 1985, "Manual of Mineralogy", 20th ed., Wiley, ISBN 0-471-80580-7
* Eastaugh, Nicholas et al., 2004, "The pigment compendium : optical microscopy of historical pigments" Oxford: Elsevier Butterworth-Heinemann, ISBN 0750645539
* [http://www.mindat.org/min-2357.html Mindat with location data]
* [http://mineral.galleries.com/minerals/silicate/lazurite/lazurite.htm Mineral galleries]
* [http://webmineral.com/data/Lazurite.shtml Webmineral data]


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Look at other dictionaries:

  • Lazurite — Catégorie IX : silicates[1] Lazurite Sar e Sang, Badakhshan, Afghanistan …   Wikipédia en Français

  • lazurite — [ lazyrit ] n. f. • 1853 en all.; lat. mod. lazur ♦ Minér. Lapis. ● lazurite nom féminin Variété de feldspathoïde proche de la haüyne, bleue, constituant principal du lapis lazuli. lazurite n. f. Syn. lapis lazuli. lazurite [lazyʀit] n. f. ÉT …   Encyclopédie Universelle

  • lazurite — [laz′yə rīt΄, lazh′yə rīt΄] n. a very rare, hard, bluish, crystalline mineral, (Na,Ca) 7 (Al,Si) 12 (O,S) 24 [SO4,Cl2 (OH) 2] 2, that is the main component of lapis lazuli …   English World dictionary

  • lazurite — noun A mineral of metamorphosed limestones. Lazurite forms the gemstone lapis lazuli, and crushed lazurite provided the ultramarine color in artists paint of the old masters. sodalite and lazurite form the sodalite group of silicate minerals. ,… …   Wiktionary

  • lazurite — lazuritas statusas T sritis chemija apibrėžtis Mineralas. formulė (Na,Ca)₈[S,SO₄,Cl|(AlSiO₄)₆] atitikmenys: angl. lazurite rus. лазурит …   Chemijos terminų aiškinamasis žodynas

  • lazurite — /laz euh ruyt , lazh euh /, n. a mineral, sodium aluminum silicate and sulfide, Na5Al3Si3O12S3, occurring in deep blue crystals, used for ornamental purposes. [1890 95; < ML lazur AZURE + ITE1] * * *       blue variety of the mineral sodalite… …   Universalium

  • lazurite — la·zu·rì·te s.f. TS mineral. minerale raro del gruppo dei feldspatoidi, di colore blu o blu violaceo e costituito spec. da silicato di sodio e calcio, che cristallizza nel sistema cubico {{line}} {{/line}} DATA: 1930. ETIMO: der. del lat. mediev …   Dizionario italiano

  • lazurite — pl.f. lazuriti …   Dizionario dei sinonimi e contrari

  • lazurite — n. dark blue mineral which is found in the semi precious gemstone lapis lazuli …   English contemporary dictionary

  • lazurite — [ lazjʊrʌɪt] noun a bright blue mineral which is the chief constituent of lapis lazuli and consists chiefly of a silicate and sulphate of sodium and aluminium …   English new terms dictionary

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