Sérandite

Na(Mn,Ca){Si(OH)}

Sérandite is certainly a major contributor in making Mont Saint-Hilaire a world famous collecting site and is arguably the most sought after mineral from the site. Three significant finds (’73, ’81 and ’88) have produced superb, aesthetic specimens up to 20cm in length.

Sérandite is the Mn end-member of the pectolite-schizolite-sérandite series and very close in being the pure end-member.

PHYSICAL CHARACTERISTICS:

Color ranges from pale pink to salmon-red, rose-red, deep orange, brown
and black; rarely in smaller crystals as colorless to tan or white.
Luster is vitreous to greasy to dull.
Diaphaneity is transparent to translucent in smaller specimens and
translucent to opaque on larger crystals; fibrous on aggregates.
Crystal System is triclinic; 1.
Crystal Habits include prismatic and tabular crystals to 20cm; acicular
to blocky to bladed forming radiating clusters and rarely as fibrous
aggregates.
Cleavage {001} and {100} are perfect.
Fracture is uneven.
Hardness is 5 – 5.5
Specific Gravity is approximately 3.35 g/cm
Streak is white.
Associated Minerals include aegirine, albite, analcime, ancylite,
astrophyllite, behoite, birnessite, calcite, fluorite, leucophanite,
mangan-neptunite, natrolite and pyrochlore.
Distinguishing Features: Crystal habit and color.
Origin: Named in 1931 after J. M. Sérand, mineral collector of West
Africa who helped in the collection of the mineral on the island of
Rouma, Los Archipelago, Guinea.

CLASSIFICATION:

Dana System
# 65.2.1.5

Strunz Classification
# VIII/F.18-80

REFERENCES:
MinRec 21:335-338 (1990), Dana 8:1320 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

MSH
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Legend

S?randite crystals - click for larger pic
Sérandite crystals
© Quintin Wight

S?randite crystals - click for larger pic
Sérandite crystals
© Stephan Wolfsried

S?randite crystals - click for larger pic
Sérandite crystals
© Stephan Wolfsried

S?randite crystals - click for larger pic
Sérandite crystals

S?randite crystals - click for larger pic
Sérandite crystals
© Quintin Wight

S?randite crystals - click for larger pic
Sérandite crystals
© Jason B. Smith

S?randite crystals - click for larger pic
Sérandite crystals
© Steven Stuart

S?randite crystals - click for larger pic
Sérandite crystals
Photo by R. Lavinsky
© www.irocks.com

S?randite crystals - click for larger pic
Sérandite crystals
Photo by R. Lavinsky
© www.irocks.com

S?randite crystals - click for larger pic
Sérandite crystals
Photo by R. Lavinsky
© www.irocks.com