Sections
Thumbnails

Donnayite-(Y) crystals - click for larger pic
Donnayite-(Y) crystals
Photo by Gilles Haineault
© Gilles Haineault

Donnayite-(Y) crystals - click for larger pic
Donnayite-(Y) crystals
Photo by Doug Merson
© Doug Merson

Donnayite-(Y) crystals - click for larger pic
Donnayite-(Y) crystals
Photo by Doug Merson
© Doug Merson

Donnayite-(Y) crystals - click for larger pic
Donnayite-(Y) crystals
Photo by Stephan Wolfsried
© Stephan Wolfsried

Search this site

Powered by FreeFind

Home > Mineral Descriptions > Donnayite-(Y) (TL) - (5 Photos)



Donnayite-(Y) (Type Locality)
Sr3NaCaY(CO3)6 · 3H2O

     Mont Saint-Hilaire is type locale for Donnayite-(Y). Crystals are usually less than 2mm in length with some exceptional crystals up to 3cms being found. Although triclinic, it exhibits trigonal and hexagonal pseudosymmetry. Some of the terminations are "capped" by ewaldite or mckelveyite.

     Donnayite-(Y) ressembles ewaldite, mckelveyite and weloganite and can be difficult to distinguish from these species.

PHYSICAL CHARACTERISTICS:

Color is varies from pale yellow to lemon-yellow, orange, pale green,
   gray, gray-green, pale brown, white and colorless.
Luster is vitreous on small crystals and waxy to dull on larger
   crystals;resinous on fractured surfaces.
Diaphaneity is transparent to translucent on smaller crystals and
   opaque on larger ones.
Crystal System is triclinic; P1.
Crystal Habits include platy, tabular, saucer- or barrel-shaped, and
   columnar; some are hemimorphic.
Cleavage: {001} indistinct to fair.
Fracture is (?).
Hardness is 3.
Specific Gravity is approximately 3.3g/cm3.
Streak is white.
Associated Minerals include aegirine, analcime, ancylite,
   arfvedsonite, microcline, natrolite, rhodochrosite and siderite.
Distinguishing Features: Crystal habit, cleavage and layered structure.
Origin: Named in 1978 after Joseph Désiré Hubert Donnay (1902-1994),
   Belgian-American-Canadian crystallographer and mineralogist, and
   Gabrielle (Hamburger) Donnay (1920-1987), American-Canadian
   mineralogist.

CLASSIFICATION:

Dana System
# 15.3.4.1

Strunz Classification
# V/D.4-10

REFERENCES:
CanMin 16:335-340 (1978), MinRec 21:305-306 (1990), Dana 8:469 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

MSH
¤¤¤

PE
¤¤

AP
¤¤

MX
¤¤

SS
¤¤

MC
¤¤

HF
¤¤

BR
¤¤

SX
--

FR
--

Legend

Donnayite-(Y) crystals - click for larger pic
Donnayite-(Y) crystals
Photo by Stephan Wolfsried
© Stephan Wolfsried