Alumohydrocalcite

General Information:
 Chemical Formula:
CaAl2(CO3)2(OH)4·3(H2O)
 Composition:
(Molecular Weight = 336.13 gm)
Calcium 11.92 % Ca
Aluminum 16.05 % Al
Hydrogen 3.00 % H 
Carbon 7.15 % C 
Oxygen 61.88 % O 
 Empirical Formula:
CaAl2(CO3)2(OH)4·3(H2O)
 Environment:
Secondary mineral associated with allophane.
 IMA Status:
Accepted IMA 1976
 Locality:
Khakassky district, Russia.
 Name Origin:
Named after its chemical composition.
Physical Properties:
 Cleavage:
[100] Perfect, [010] Imperfect
 Color:
chalky white, bluish white, violet, light yellow, or gray.
 Density:
2.23
 Diaphaniety:
Transparent to subtranslucent
 Habits:
Spherical - Spherical, rounded aggregates., Acicular - Occurs as needle-like crystals., Massive - Fibrous - Distinctly fibrous fine-grained forms.
 Hardness:
2.5 - Finger Nail
 Luster:
Vitreous (Glassy)
 Streak:
white
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