Not to be confused with Lazurite or Lapis lazuli.
For other uses, see Azure spar.

Lazulite or Azure spar[6]: 14  is a transparent to semi-opaque, blue mineral that is a phosphate of magnesium, iron, and aluminium, with the chemical formula (Mg,Fe2+)Al2(PO4)2(OH)2.[3] Lazulite forms one endmember of a solid solution series with the darker, iron-rich scorzalite.[3][5]

Lazulite crystallizes in the monoclinic system. Its crystal habits include steep bipyramidal or wedge-shaped crystals.[7] Lazulite has a Mohs hardness of 5.5–6.0 and a specific gravity of 3.0–3.1. It is infusible and insoluble.[5]

Occurrence and discovery

Lazulite from Laila, Gilgit District, Gilgit-Baltistan, Pakistan. Size: 2.4 cm × 1.7 cm × 0.8 cm (0.94 in × 0.67 in × 0.31 in).

Lazulite forms by high-grade metamorphism of silica-rich rocks and in pegmatites. It occurs in association with quartz, andalusite, rutile, kyanite, corundum, muscovite, pyrophyllite, dumortierite, wagnerite, svanbergite, trolleite, and berlinite in metamorphic terrains; and with albite, quartz, muscovite, tourmaline and beryl in pegmatites.[2] It may be confused with lazurite, lapis lazuli or azurite.

The type locality is in Freßnitzgraben in Krieglach, it's also found in Salzburg, Austria; Zermatt, Switzerland; Minas Gerais, Brazil; Lincoln County, Georgia; Inyo County, California; the Yukon in Canada; and elsewhere.

It was first described in 1795 for deposits in Styria, Austria.[3] Its name comes from the German lazurstein, for 'blue stone'[2] or from the Arabic for heaven.[3][5]

References

  1. ^ Warr, L. N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3). Mineralogical Society of Great Britain and Ireland: 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b c "Lazulite" (PDF). Handbook of Mineralogy. RRUFF. Archived (PDF) from the original on Jul 5, 2021.
  3. ^ a b c d e "Lazulite". Mindat.org.
  4. ^ Lazulite Mineral Data, WebMineral.com
  5. ^ a b c d Hurlbut, Cornelius S.; Klein, Cornelius (1985). Manual of Mineralogy (20th ed.). Wiley. ISBN 0-471-80580-7.
  6. ^ Krivovichev V. G. Mineralogical glossary. Scientific editor A. G. Bulakh. — St.Petersburg: St.Petersburg Univ. Publ. House. 2009. — 556 p. (in Russian)
  7. ^ "Lazulite". Minerals.net.
Allikas: https://en.wikipedia.org/wiki/Lazulite
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