General Information:
Chemical Formula:
As
Composition:
(Molecular Weight = 74.92 gm)
Arsenic 100.0 % As
Empirical Formula:
As
Environment:
In ore veins in crystalline rocks.
Locality:
Saxony, Great Britain.
Name Origin:
From the Greek, Arsenikon, a name originally applied to the mineral orpiment.
Physical Properties:
Cleavage:
[0001] Perfect
Color:
lead gray, gray, or white.
Density:
5.7
Diaphaniety:
Opaque
Habits:
Nodular - Tuberose forms having irregular protuberances over the surface., Reniform - "Kidney like" in shape (e.g.. hematite)., Lamellar - Thin laminae producing a lamellar structure.
Hardness:
3.5 - Copper Penny
Luminescence:
None.
Luster:
Diagnostic tests : Arsenides, sulpharsenites, etc. (As 2- ), give off fumes when roasted on charcoal, usually easily recognized by their peculiar garlic odor. In the open tube test, they give a white, volatile, crystalline sublimate of As 2 O 3 . In the closed tube test with sulfur, they yield a sublimate of dark brown-red when hot and red or reddish yellow when cold; or a black to gray mirror sublimate of metallic arsenic. Arsenates (AsO 4 ) can be detected by the garlic odor yielded when a mixture of the powdered mineral with charcoal dust and Na 2 CO 3 is heated with a reducing flame on charcoal.
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