Lazulite

lazulite

rutile

kyanite

svanbergite

Images

Formula: MgAl2(PO4)2(OH)2
Anhydrous phosphate containing hydroxyl, lazulite group
Crystal System: Monoclinic
Specific gravity: 3.122 to 3.24 measured, 3.144 calculated
Hardness: 5½ to 6
Streak: White
Colour: Blue, sky-blue, bluish white
Solubility: Slowly soluble in hot acids
Common impurities: Fe,Mn
Environments

Pegmatites
Sedimentary environments
Metamorphic environments

Lazulite occurs disseminated in quartzite, schist and quartz veins, in the border zones of complex granite pegmatites, and in sediments.
In metamorphic environments associated minerals include quartz, andalusite, rutile, kyanite, corundum, muscovite, pyrophyllite, dumortierite, wagnerite, svanbergite and berlinite.
In pegmatites associated minerals include albite, quartz, muscovite, tourmaline and beryl (HOM)

Localities

Near Werfen, St. Johann im Pongau District, Salzburg, Austria, lazulite occurs with wagnerite in quartz carbonate veins in clay slate (Dana).

At the type locality, Freßnitzgraben, Krieglach, Bruck-Mürzzuschlag District, Styria, Austria, lazulite occurs associated with wagnerite (Mindat).

At the Cotamitos mine, Cerro de Potosí, Potosí City, Potosí Department, Bolivia, lazulite occurs as pseudomorphs with sericite after orthoclase (Dana).

At Datas, Minas Gerais, Brazil, lazulite occurs in quartz veins in sericitic quartzite with quartz, sericite and rutile (Dana, AM 35.1-18).

At Tribeč Mountain, Kovarce, Topoľčany, Nitra Region, Slovakia, lazulite occurs in quartz veins in quartzite (Dana).

At the Västanå Iron Mine, Näsum, Bromölla, Skåne County, Sweden, lazulite occurs with berlinite (Dana).

At Hålsjöberg, Torsby, Värmland County, Sweden, lazulite occurs with svanbergite (Dana).

At Markleeville, Alpine county, California, USA, lazulite occurs with andalusite and rutile in garnetiferous quartzite (Dana).

At Breyfogle Mine, Panamint Treasure claim group, Gold Hill, Gold Hill District, Carbonate District, Panamint Mts, Inyo county, California, USA, lazulite occurs in a quartz vein associated with quartz, muscovite and rutile (AM 35.1-18).

At Champion Mine (Black Eagle), White Mountain Peak, White Mountains, Mono county, California, USA, lazulite occurs in a quartz dike in schist, with andalusite, quartz, calcite and hematite (Dana, AM 35.1-18).

At Graves Mountain, Lincoln county, Georgia, USA, lazulite occurs in sericitic quartzite with quartz, kyanite, rutile, staurolite, garnet and pyrophyllite (Dana, AM 35.1-18).

At the Keyes Mica Quarries, Orange, Grafton County, New Hampshire, USA, the pegmatites are beryl-type rare-element (RE) pegmatites.
The Number 1 mine exposed a pegmatite that shows the most complex zonation and diverse mineralogy of any of the Keyes pegmatites. Six zones are distinguished, as follows, proceeding inward from the margins of the pegmatite:
(1) quartz-muscovite-plagioclase border zone, 2.5 to 30.5 cm thick
(2) plagioclase-quartz-muscovite wall zone, 0.3 to 2.4 metres thick
(3) plagioclase-quartz-perthite-biotite outer intermediate zone, 0.3 to 5.2 metres thick, with lesser muscovite
(4) quartz-plagioclase-muscovite middle intermediate zone, 15.2 to 61.0 cm thick
(5) perthite-quartz inner intermediate zone, 0.9 to 4.6 meters thick
(6) quartz core, 1.5 to 3.0 metres across
The inner and outer intermediate zones contained perthite crystals up to 1.2 meters in size that were altered to vuggy albite-muscovite with fluorapatite crystals. This unit presumably was the source of the albite, muscovite, fluorapatite, quartz and other crystallised minerals found in pieces of vuggy albite rock on the dumps next to the mine.
The middle intermediate zone produced sheet mica with accessory minerals including tourmaline, graftonite, triphylite, vivianite, pyrite, pyrrhotite, and beryl crystals to 30.5 cm long and 12.7 cm across.
Lazulite is found as small, bright blue patches with graftonite. Scorzalite occurs in close association with the lazulite (R&M 97.4.320).

At Clubb Mountain Kyanite Prospects, Lincolnton, Gaston county, North Carolina, USA, lazulite occurs in a quartz-kyanite vein in quartzite with quartz, kyanite, rutile, staurolite, garnet and pyrophyllite (AM 35.1-18).

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