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Formula: MgSn(OH)6
Hydroxide, schoenfliesite subgroup, forms a series with
wickmanite,
tin-bearing mineral
Crystal System: Isometric
Specific gravity: 3.32 measured, 3.483 calculated
Hardness: 4 to 4½
Streak: Nearly white, lighter than massive mineral
Colour: Dark red-brown, yellow, orange, greenish yellow
Solubility: Soluble in hydrochloric acid and slowly soluble in NaOH and in NH4OH
Environments
Metamorphic environments
Hydrothermal environments
Schoenfliesite occurs in serpentinised
dolostone in contact with
boron-beryllium-strontium-tungsten
skarn. Associated minerals include
berborite, calcite,
cassiterite, chondrodite,
diopside, dolomite,
fluorite and magnetite
(Mindat).
Localities
At Lake Ladoga, Republic of Karelia, Russia, schoenfliesite occurs in
chlorite-serpentine rock,
associated with chondrodite,
diopside, fluorite,
calcite, dolomite and
magnetite
(Dana).
At the Pitkyaranta mining district, Ladoga Region, Republic of Karelia, Russia, schoenfliesite occurs as a low
temperature mineral in serpentinised
dolostone associated with
boron-beryllium-strontium-tungsten
skarn. It has been found in lumps of
chlorite-serpentine rock from
a mine dump. This rock commonly contains relicts of chondrodite and
diopside, as well as grains, lenses, and small veins of
fluorite, calcite,
dolomite and magnetite. Spread in
this matrix are small groups of prismatic crystals of cassiterite from a
few mm to 7 cm long. The cassiterite is often covered with a fibrous
crust of schoenfliesite, from 0.01-0.15 mm thick; the schoenfliesite is overgrown by a crust of
calcite or fluorite, or by
fluorite and then calcite.
Associated minerals include cassiterite,
berborite, calcite,
fluorite, dolomite,
magnetite, chondrodite and
diopside
(CM 15.437-445, HOM).
At the type locality, Brooks Mountain, Seward Peninsula, Nome Census Area, Alaska, USA, schoenfliesite is
a late-stage hydrothermal alteration product of hulsite in a boron-metasomatised
limestone near the contact with a
granite intrusive. Associated minerals include
maghemite, hulsite,
goethite, magnetite,
fluorite and hematite
(HOM, Dana, Mindat).
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