Lazulite
(same H–M symbol)
c = 7.228(1) [Å]; β = 120.5(1)°; Z = 2
nβ = 1.626–1.654
nγ = 1.637–1.663
Lazulite 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.[6] 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
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/f6/Lazulite-dtn2a.jpg/170px-Lazulite-dtn2a.jpg)
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
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
- ^ 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.
- ^ a b c "Lazulite" (PDF). Handbook of Mineralogy. RRUFF. Archived (PDF) from the original on Jul 5, 2021.
- ^ a b c d e Lazulite, Mindat.org
- ^ Lazulite Mineral Data, WebMineral.com
- ^ a b c d Hurlbut, Cornelius S.; Klein, Cornelius (1985). Manual of Mineralogy (20th ed.). Wiley. ISBN 0-471-80580-7.
- ^ "Lazulite". Minerals.net.