NaZrSi
Parakeldyshite is rare at MSH, and it is probably due to the fact it is so easy to overlook the crystals due to their transparency and color. It does display orange-white fluorescence under SW.
PHYSICAL CHARACTERISTICS:
Color is usually colorless.
Luster is vitreous.
Diaphaneity is transparent.
Crystal System is orthorhombic; 1.
Crystal Habits include irregular grains and embedded crystalline masses
to 6mm.
Cleavage {001} is perfect, {110} is good.
Fracture is conchoidal.
Hardness is 5.5 – 6.
Specific Gravity is approximately 3.4 g/cm
Streak is white.
Associated Minerals include aegirine, albite, amphibole group,
analcime, chabazite, epistolite, eudialyte, gmelinite, gonnardite,
magnesio-arfvedsonite, sodalite, steenstrupine and zircon.
Distinguishing Features: Crystal habit, color and transparency.
Origin: Named in 1977 from the Greek para, near, and keldyshite,
for its similarity to that mineral.
CLASSIFICATION:
Dana System
# 55.2.2.3
Strunz Classification
# VIII/C.04-20
REFERENCES:
MinRec 21:327 (1990), Dana 8:1140 (1997)
DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:
MSH
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