Chemical Formula: Mn4(Be3Si3O12)S
Locality: Schwarzenberg and Breitenbrunn, Germany.
Name Origin: From the Greek helios – “sun.”
Physical Properties
Cleavage: {111} Indistinct, {111} Indistinct, {111} Indistinct
Color: Brown, Brownish yellow, Gray, Yellow, Yellow green.
Density: 3.16 – 3.36, Average = 3.26
Diaphaneity: Translucent to opaque
Fracture: Brittle – Generally displayed by glasses and most non-metallic minerals.
Hardness: 6-6.5 – Orthoclase-PyriteLuminescence: Fluorescent, Short UV=deep red, Long UV=deep red.
Luster: Vitreous – Resinous
Streak: grayish white
Photos :
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