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Formula: Fe2+Al2(PO4)2(OH)2
Anhydrous phosphate containing hydroxyl, lazulite group, and forms a series with
lazulite
Crystal System: Monoclinic
Specific gravity: 3.33 measured, 3.32 calculated
Hardness: 6
Streak: White to light blue
Colour: Dark azure blue, green-blue, blue-green
Environments
Pegmatites
Metamorphic environments
Lazulite and scorzalite occur as
secondary minerals in
pegmatites in many regions where metamorphic rocks
are intruded by granitic rocks. The metamorphic rocks commonly exhibit
high-grade
metamorphism. The phosphate minerals intimately associated with lazulite or
scorzalite
in these regions include fluorapatite,
lacroixite, triphylite,
wyllieite, wagnerite,
berlinite, svanbergite,
attakolite,
trolleite,
augelite, brazilianite and
souzalite. Admixed aluminum-rich
minerals include
kyanite, andalusite,
sillimanite, corundum,
pyrophyllite, spinel,
dumortierite and almandine -
spessartine garnet. Other
associated minerals
are quartz, microcline,
muscovite, beryl,
tourmaline, rutile,
ilmenite, hematite,
magnetite, pyrite,
chalcopyrite, calcite,
siderite and aragonite.
Lazulite and scorzalite are common accessory minerals in (1)
mica deposits in the United States, Brazil and eastern Siberia,
(2) andalusite deposits in California and Armenia, (3)
diamond and gold placers in Brazil, (4)
corundum variety sapphire placers in the Himalaya Mountains and (5)
quartz crystal deposits in the Ural Mountains.
Quartz-rich veins and dikes containing
lazulite or
scorzalite occur in quartzite,
quartzitic schist and
gneiss. The lazulite or
scorzalite occurs as irregular masses or, rarely, as faceted crystals in druses.
Andalusite,
rutile, kyanite,
muscovite and pyrophyllite
are common
mineral associates.
Lazulite or scorzalite in
granitic
pegmatites selectively occur in the border zone rather than
in the central zone. A number of other phosphate minerals,
plagioclase, quartz,
muscovite, tourmaline and
beryl are the common mineral associates in this environment
(AM 35.1-18, HOM, Mindat).
Localities
At the type locality, the Córrego Frio mine, Linópolis, Divino das Laranjeiras, Minas Gerais, Brazil, scorzalite
occurs in a pegmatite principally in the border zone and
outer margin of the crystal cavity zone. The largest mass of scorzalite observed
is about 7 cm across, and the masses are rarely free from admixed souzalite
(AM 34.83-93).
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.
Scorzalite occurs as massive, bright blue material from the Keyes No. 1 mine. Associated minerals include
fairfieldite(?), hureaulite,
jahnsite-group species and pyrite. A
graftonite specimen found at the No. 1 mine contains both scorzalite
and lazulite
(R&M 97.4.324-325).
At the Victory Mine, Custer, Custer Mining District, Custer county, South Dakota, USA,
mica-bearing pegmatite
is internally divided into a wall zone composed essentially of plagioclase,
quartz and muscovite, and a core of
feldspar variety perthite and quartz.
Scorzalite was found
principally in the wall zone. In all the hand specimens available, scorzalite occurs only in
pegmatite with
quartz, plagioclase,
muscovite, tourmaline and
triphylite. The scorzalite is massive and intimately intergrown with the
tourmaline, triphylite, and
muscovite
(AM 34.685-687).
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