Best viewed using Adobe Flash Player (8 or higher).
Download here

Acanthite

Acanthite

MNHN N°206.97

visu_54 infos
FROM : Imiter mines, Djebel, Sahro, Morroco
SIZE : 7.5 x 3.6 cm

general description

This specimen shows a dendritic aggregate of pseudo-octahedral crystals of acanthite, gray-black to black in colour. This acanthite is a pseudomorphosis on argentite (also a silver sulphide).

The octahedral crystals measure 0.5 cm on average (cf. detail 1); the whole sample measuring 7.5 x 3.6 cm.

This specimen comes from the Imiter mines, a famous silver-bearing mineral deposit. The Muséum national d’Histoire naturelle obtained it thanks to support from Total. It is kept in the storage rooms of the collections (i.e., not yet displayed to the public).

Photography: Louis-Dominique Bayle, © MNHN.
The Species page
Identity card
SPECIE : Acanthite

HISTORY : Name inspired from the Greek word "ακαντα" [akanta] meaning "arrow", in reference to its crystal shapes

Species first described in 1855 by Gustav Adolf Kenngott (1818-1897), Swiss mineralogist

Type-locality: Jachimov, Czech Republic

CHEMICAL FORMULA : Ag2S
CRYSTAL SYSTEM : Monoclinic
COLOR : Black, grayish
DIAPHANIETY : Opaque
LUSTER : Metallic
STREAK : Lead gray
MORPHOLOGY : Crystals sometimes prismatic, more often cubo-octahedric
HARDNESS : 2,0-2,5
DENSITY : 7,24

CHEMICAL CLASS : II - Sulfides, arsenides
GROUP : Acanthite
STRUNZ CLASS BEFORE 2001 : 2/B.05-10
STRUNZ CLASS AFTER 2001 : 2.BA.25
back
9
PREVIOUS
CLOSE

Mineralogy

Explore the Mineral Treasures of the Muséum
Welcome to
the Virtual Gallery of Mineralogy

This site was made possible thanks to support from TOTAL

VIEW FULL SCREEN
VERSION FRANÇAISE