(Na,Ca,K)(Nb,Ti)Si(O,OH) · 2H
Several nice nenadkevichite crystals have been found at Mont Saint-Hilaire, it is also found as pseudomorphs after sérandite. The labuntsovite-nenadkevichite series is expanding rapidly, there are probably several members present at mont Saint-Hilaire.
PHYSICAL CHARACTERISTICS:
Color ranges from colorless to pale pink, pale yellow, rose-pink,
orange and brownish red.
Luster is vitreous to pearly or dull; some crystals are coated by
a thin iridescent film.
Diaphaneity is transparent to translucent for the crystals and
opaque for the aggregates.
Crystal System is orthorhombic; Pbam
Crystal Habits include masses to several cm across of intergrown
small crystals. Superb 1-8mm prismatic and very thin tabular single
crystals as stacked clusters of compact spherical aggregates.
Cleavage {010} is poor.
Fracture is uneven.
Hardness is 5
Specific Gravity is approximately 2.7 to 2.8g/cm
Streak is white.
Associated Minerals include aegirine, albite, amphibole group,
analcime, ancylite, astrophyllite, bastnäsite, calcite, catapleiite,
chlorite group, donnayite, elpidite, epididymite, eudialyte, fluorapatite,
fluorite, hilairite, mangan-neptunite, microcline, monteregianite,
natrolite, polylithionite, pyrite, pyrochlore, rhodochrosite, rutile,
sérandite, sphalerite, steacyite and yofortierite.
Distinguishing Features: Crystal habit and color.
Origin: Named in 1955 after Konstantin Antonomovich Nenadkevich
(1880-1963), geochemist and mineralogist, Institute of Mineralogy
and Geochemistry of Rare Elements, Moscow, Russia.
CLASSIFICATION:
Dana System
# 60.1.3.1
Strunz Classification
# VIII/E.07-140
REFERENCES:
MinRec 21:326 (1990), AmMin 40:1154 (1955), Dana 8:1234 (1997)
DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:
MSH
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Nenadkevichite crystals
© Modris Baum
Nenadkevichite crystals
© Jason B. Smith
Nenadkevichite crystals
© Doug Merson
Nenadkevichite crystals
© Stephan Wolfsried
Nenadkevichite crystals
© Stephan Wolfsried
Nenadkevichite crystals
© Stephan Wolfsried
Nenadkevichite scepters
© Steven Stuart
Nenadkevichite crystals
© Jason B. Smith
Nenadkevichite crystals
© Doug Merson
Nenadkevichite crystals
© Stephan Wolfsried
Nenadkevichite scepters
© Steven Stuart
Nenadkevichite crystals
© Doug Merson