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Ewaldite crystals - click for larger pic
Ewaldite crystals
Gary Glenn specimen
Photo by Violet Anderson
© Royal Ontario Museum

Ewaldite crystals - click for larger pic
Ewaldite crystals
Photo by Violet Anderson
© Royal Ontario Museum

Ewaldite crystals - click for larger pic
Ewaldite crystals
© Doug Merson

Ewaldite crystals - click for larger pic
Ewaldite crystals
© Stephan Wolfsried

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Home > Mineral Descriptions > Ewaldite - (6 Photos)



Ewaldite
Ba(Ca,Y,Na,K)(CO3)2

     Ewaldite is relatively rare at Mont Saint-Hilaire. It is very difficult to distinguish from mckelveyite-(Y). The epitactic overgrowth of donnayite-(Y) should help with the identification. On most of the accompanying photos you will find a cap of donnayite-(Y).

PHYSICAL CHARACTERISTICS:

Color ranges from off-white, beige, yellow-brown, yellow-green,
   greenish-gray to dark bluish gray.
Luster is greasy or dull.
Diaphaneity is opaque.
Crystal System is hexagonal; P63mc.
Crystal Habits include sharp hexagonal hemimorphic crystals to
   3mm, with some groups of crystals to 10mm.
Cleavage none observed.
Fracture is (??).
Hardness is 3.
Specific Gravity is approximately 3.25 g/cm3.
Streak is white.
Associated Minerals include aegirine, albite, analcime, ancylite,
   apophyllite series, calcite, leucosphenite, molybdenite,
   monteregianite, narsarsukite and quartz.
Distinguishing Features: Crystal habit.
Origin: Named in 1971 after Paul Peter Ewald (b. 1888), physicist
   and crystallographer, Polytechnic Institute of New York, U.S.A.

CLASSIFICATION:

Dana System
# 14.2.4.1

Strunz Classification
# V/D.04-05

REFERENCES:
MinRec 21:309 (1990), Dana 8:453-454 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

MSH
¤¤¤

PE
--

AP
--

MX
--

SS
--

MC
¤¤

HF
--

BR
¤¤

SX
--

FR
--

Legend

Ewaldite crystals - click for larger pic
Ewaldite crystals
© Saul Krotki

Ewaldite crystals - click for larger pic
Ewaldite crystals
© Stephan Wolfsried