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Micheelsenite crystals
co-type specimen
Photo by Quintin Wight
© Quintin Wight
Micheelsenite crystals
© Jason B. Smith
(Ca,Y)Al(POOH,CO)(CO)(OH) · 12H
The oldest remaining unknown at MSH, UK-#32, has finally been resolved. It forms lovely aggregates of acicular crystals with striations along the length of the crystals. Mont Saint- Hilaire is the co-type locality with the Nanna pegmatite, Narsaarsuup Qaava, South Greenland.
PHYSICAL CHARACTERISTICS:
Color is white to colorless.
Luster is vitreous.
Diaphaneity: translucent to transparent, rounded plates are opaque.
Crystal System is hexagonal,
Crystal Habits acicular to fibrous crystals forming spherical aggregates,
bundles of randomly oriented, hair-like matted fibres, small rounded
plates in hornfels.
Cleavage {100} and {001} are good.
Fracture is splintery.
Hardness is 3,5 – 4.
Specific Gravity is approximately 2,15 g/cm
Streak is white.
Associated Minerals include aegirine, albite, ancylite, calcite, catapleiite,
fluorite, microcline, monteregianite, natrolite, nenadkevichite, pyrite,
rhodochrosite, sérandite and titanite.
Distinguishing Features include striations along [001] and terminated
by pedion {001}.
Origin: Named in 2001, after Dr H.I. Micheelsen (b 1931), discoverer of
the Nanna pegmatite in South Greenland (co-type locality).
CLASSIFICATION:
Dana System
# 43.5.22.1
Strunz Classification
# V/C.07-210
REFERENCES:
NJM: 8 337-351 (2001)
DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:
MSH
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