Schairerite

General Information:
 Chemical Formula:
Na21(SO4)7F6Cl
 Composition:
(Molecular Weight = 1,304.67 gm)
Sodium 37.00 % Na
Sulfur 17.20 % S 
Chlorine 2.72 % Cl
Oxygen 34.34 % O 
Fluorine 8.74 % F 
 Empirical Formula:
Na21(SO4)7F6Cl
 Environment:
Continental evaporite deposits.
 Locality:
Drill core from the lower salt member at Searles Lake, San Bernardino Co., California.
 Name Origin:
Named for John Frank Schairer (1904-1970), American physical chemist, Geophysical Laboratory, Washington, DC, USA.
Physical Properties:
 Cleavage:
[???] Indistinct
 Color:
colorless.
 Density:
2.61
 Diaphaniety:
Transparent
 Habits:
Rhombohedral Crystals - Occurs as well-formed crystals showing rhobohedral crystals., ,
 Hardness:
3.5 - Copper Penny
 Luminescence:
Non-fluorescent.
 Luster:
Vitreous (Glassy)
 Streak:
white
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