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Helvite Pictures

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Helvite from the Navegador mine, Conselheiro Pena, Minas Gerais, Brazil

CHEMISTRY - Mn₄Be₃(SiO₄)₃S

CRYSTALLOGRAPHY - Cubic

CRYSTAL GROWTH AND HABITS - Helvite often forms tetrahedral crystals or pseudo octahedral crystals and also dodecahedral crystals.  It can also be found as rounded grains.

COLOR AND OPTICAL PROPERTIES - Yellow to brown and grayish yellow to yellowish green

HARDNESS - 6 - 6.5

SPECIFIC GRAVITY - 3.20 - 3.44

LUSTER - Vitreous to sub vitreous and resinous

STREAK - White

BREAKABILITY - Helvite has a distinct cleavage on {111} and {111}.  It also displays uneven to conchoidal fracture.  It is brittle.

OCCURRENCE - Helvite is found in granite and granitic pegmatites as well as high grade metamorphic rocks like gneiss.  It has also been found in skarns and contact metamorphic zones.

ASSOCIATED MINERALS - Helvite is found with Garnet, Fluorite, Quartz, Magnetite, Chlorite, Vesuvianite and Diopside.

MINERAL NAME - Helvite is derived from the Greek for sun, due to its yellowish color.

CHEMISTRY -

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OCCURRENCE -

ASSOCIATED MINERALS -

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