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Cryptomelane
K(Mn4+,Mn2+)8O16

     Found at mont Saint-Hilaire a few decades ago, there was some questions about its identity and this species had originally been designated as pyrolusite. Recent analysis in 2006 has confirmed its status and identity.

PHYSICAL CHARACTERISTICS:

Color is predominantly brownish black to black.
Luster is sub-metallic to earthy.
Diaphaneity is opaque.
Crystal System is monoclinic; I2m.
Crystal Habits include botryoidal rounded forms.
Cleavage: (??).
Fracture is conchoidal.
Hardness is 6 - 6.5
Specific Gravity is approximately 4.36 g/cm3.
Streak is brownish black.
Associated Minerals include (??).
Distinguishing Features: Brittle. No fluorescence observed.
Origin: Named in 1942 from the Greek for hidden and black, as the identity of this common black manganese mineral had been lost within the group of such minerals.

CLASSIFICATION:

Dana class # 7.9.1.2

Strunz class # IV/D.08-20

REFERENCES:
Dana 8:321-322 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

MSH
¤¤¤

PE
--

AP
--

MX
--

SS
--

MC
--

HF
--

BR
--

SX
--

FR
--

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