Kellyite

General Information:
 Chemical Formula:
(Mn++,Mg,Al)3(Si,Al)2O5(OH)4
 Composition:
(Molecular Weight = 323.85 gm)
Magnesium 7.51 % Mg
Manganese 25.45 % Mn
Aluminum 8.33 % Al
Silicon 13.01 % Si
Hydrogen 1.24 % H 
Oxygen 44.46 % O 
 Empirical Formula:
Mn2+1.5MgAl0.5Si1.5Al0.5O5(OH)4
 Environment:
Metamorphic Mn deposit with other Mn-silicates.
 IMA Status:
Approved IMA 1974
 Locality:
Bald Knob, Sparta, Alleghany County, North Carolina, USA.
 Name Origin:
Named for William Crowley Kelley (1929-), American geologist, University of Michigan.
Physical Properties:
 Cleavage:
[001] Perfect
 Color:
golden yellow or lemon yellow.
 Density:
3.07
 Diaphaniety:
Transparent
 Habits:
Micaceous - Platy texture with "flexible" plates., Lath - Shaped like a small, thin plaster lath, tabular (rectangular) in shape., Tabular - Form dimensions are thin in one direction.
 Hardness:
2.5 - Finger Nail
 Luster:
Vitreous - Resinous
 Streak:
yellowish white
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