Acanthite

n. form of silver sulfide

Argentite, a mineral which belongs to the galena group, is cubic silver sulfide (Ag₂S). It is occasionally found as uneven cubes and octahedra, but more often as dendritic or earthy masses, with a blackish lead-grey color and metallic lustre. The cubic cleavage, which is so prominent a feature in galena, here present only in traces. The mineral is perfectly sectile and has a shining streak; hardness 2.5, specific gravity 7.3. It occurs in mineral veins, and when found in large masses, as in is Mexico and in the Comstock Lode in Nevada, it forms an important ore of silver. The mineral was mentioned 1529 by G. Agricola, but the name argentite (from the Lat. argentum, silver) was not used till 1845 and is due to W. Haidinger. Old names for the species are Glaserz, silver-glance and vitreous silver. A cupriferous variety, from Jalpa in Mexico, is known as jalpaite.
See more at Wikipedia.org...

General Information:
 Chemical Formula:
Ag2S
 Composition:
(Molecular Weight = 247.80 gm)
Silver 87.06 % Ag
Sulfur 12.94 % S 
 Empirical Formula:
Ag2S
 Name Origin:
From the Greek, akanta, meaning "arrow." After the Latin, argentum, meaning "silver". Argentite is stable above 179 C. Acanthite is stable below 179 C.
Physical Properties:
 Cleavage:
[001] Poor, [110] Poor
 Color:
lead gray, gray, or black.
 Density:
7.2 - 7.4, Average = 7.3
 Diaphaniety:
Opaque
 Habits:
Blocky - Crystal shape tends to be equant (e.g. feldspars)., Skeletal - Crystals form crude outlines with missing faces., Arborescent - "Tree like" growths of branched systems (e.g. s ilver).
 Hardness:
2-2.5 - Gypsum-Finger Nail
 Luminescence:
None.
 Luster:
Metallic
 Streak:
shining black
More details...

ARGENTITE

B: (Biologi) akantit
Built to Babylon by Hikmat Gumilar Visit my Website;