Sections
Thumbnails

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

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

Search this site

Powered by FreeFind

Home > Mineral Descriptions > Magnesioarfvedsonite - (2 Photos)



Magnesioarfvedsonite
Na3(Mg,Fe2+)4Fe3+Si8O22(OH)2

     Magnesio-arfvedsonite, a member of the amphibole group, is very rare at MSH. It is almost identical to arfvedsonite in appearance and is indistinguishable visually.

PHYSICAL CHARACTERISTICS:

Color varies from blue-green to black.
Luster is vitreous to dull.
Diaphaneity is translucent to opaque.
Crystal System is monoclinic; C2/m.
Crystal Habits include prismatic crystals to 9cm and fine-
   grained matrix material.
Cleavage {110} is perfect.
Fracture is uneven to subconchoidal.
Hardness is 5 - 6.
Specific Gravity is approximately 3.3 g/cm3.
Streak is dark bluish-gray.
Associated Minerals include aegirine, albite, analcime, ancylite
   biotite, calcite, catapleiite, eudialyte, fluorite, microcline, narsarsukite,
   natrolite, petarasite, polylithionite, rhodochrosite and titanite. Distinguishing Features: Crystal habit and color.
Origin: Named in 1957 as the magnesium-dominant analog of
   arfvedsonite.

CLASSIFICATION:

Dana System
# 66.1.3c.8

Strunz Classification
# VIII/F.8-90

REFERENCES:
MinRec 21:321 (1990), Dana 8:1364-1365 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

MSH
¤¤¤

PE
--

AP
--

MX
¤¤

SS
--

MC
--

HF
--

BR
--

SX
--

FR
--

Legend