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Helvite crystals - click for larger pic
Helvite crystal
C. M. N. sp.
Photo by Violet Anderson
© Royal Ontario Museum

Helvite crystals - click for larger pic
Helvite crystals
© Modris Baum

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Home > Mineral Descriptions > Helvite - (2 Photos)



Helvite
Mn4Be3(SiO4)3S

     Helvite, a member of the danalite-helvite-genthelvite series, is far less abundant than genthelvite at MSH. Helvite fluoresces intense deep red under LW and SW.

PHYSICAL CHARACTERISTICS:

Color is varies from bright yellow to lemon-yellow, orange-yellow.
Luster is vitreous, resinous on granular inclusions.
Diaphaneity: transparent to translucent, opaque on granular inclusions.
Crystal System is isometric; P43n.
Crystal Habits include small tetrahedra to 3mm on edge, with
   minor faces truncating the apices of the tetrahedra, free-growing
   crystals granular inclusions.
Cleavage {111} is distinct.
Fracture is not apparent.
Hardness is 6.
Specific Gravity is approximately 3.1 g/cm3.
Streak is white.
Associated Minerals include aegirine, analcime and catapleiite.
Distinguishing Features: Crystal habit and fluorescence.
Origin: Named in 1817 from the Greek helios, sun, alluding
   to its yellow color.

CLASSIFICATION:

Dana System
# 76.2.4.1

Strunz Classification
# VIII/J.12-20

REFERENCES:
MinRec 21:314 (1990), Dana 8:1630-1631 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

MSH
¤¤¤

PE
--

AP
¤¤

MX
¤¤

SS
--

MC
--

HF
--

BR
--

SX
--

FR
--

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