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Garronite crystals
© Gilles Haineault
Garronite crystals
© Doug Merson
Garronite crystals
© Modris Baum
NaCaAl12Si2064 · 27H
Garronite is extremely rare at MSH. It has orthorhombic symmetry though it has a pseudo-tetragonal aspect.
PHYSICAL CHARACTERISTICS:
Color is usually pale yellow, orange-yellow or yellowish brown.
Luster is dull to greasy.
Diaphaneity is transparent to translucent.
Crystal System is orthorhombic; 2.
Crystal Habits include very small prisms that form globular and
crude aggregates of tetragonal dipyramids to 2mm across.
Cleavage {100} and {010} are good.
Fracture is uneven.
Hardness is 4 – 4.5
Specific Gravity is approximately 2.15 g/cm
Streak is white.
Associated Minerals include aegirine, eudialyte, microcline,
natrolite, sodalite and villiaumite.
Distinguishing Features: Crystal habit.
Origin: Named in 1962 after its discovery locality, in the
Garron Plateau, County Antrim, Northern Ireland.
CLASSIFICATION:
Dana System
# 77.1.3.3
Strunz Classification
# VIII/J.25-40
REFERENCES:
MinRec 21:311 (1990), Dana 8:1662-1663 (1997)
DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:
MSH
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Garronite crystals
© Modris Baum