Aguilarite

Aguilarite (Ag4SeS) is a mineral found in the San Carlos mine in Mexico.
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General Information:
 Chemical Formula:
Ag4SeS
 Composition:
(Molecular Weight = 542.50 gm)
Silver 79.53 % Ag
Selenium 14.55 % Se
Sulfur 5.91 % S 
 Empirical Formula:
Ag4SeS
 Environment:
Low temperature silver mineral in deposits rich in selenium.
 Locality:
TL: Mexico, Guanajuato, San Carlos mine.
 Name Origin:
Named for Ponciano Aguilar (1853-1935), superintendent of the San Calos mine, Guanajuato, where the mineral was found.
Physical Properties:
 Cleavage:
None
 Color:
gray, iron gray, or black.
 Density:
7.4 - 7.56, Average = 7.48
 Diaphaniety:
Opaque
 Habits:
Massive - Uniformly indistinguishable crystals forming large masses., ,
 Hardness:
2-3 - Gypsum-Calcite
 Luminescence:
Non-fluorescent.
 Luster:
Adamantine - Metallic
 Streak:
grayish black
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