General Information:
Chemical Formula:
[ ](CaNa)Fe++4(Al,Fe+++)Si8O22(OH)2
Composition:
(Molecular Weight = 931.34 gm)
Sodium 2.47 % Na
Calcium 4.30 % Ca
Aluminum 2.17 % Al
Iron 25.48 % Fe
Silicon 24.12 % Si
Hydrogen 0.22 % H
Oxygen 41.23 % O
Empirical Formula:
CaNaFe2+4Al0.75Fe3+0.25(Si8O22)(OH)2
IMA Status:
Approved IMA 1978
Name Origin:
Named for its composition and for Howard J. Winch, Geological survey of India.
Physical Properties:
Cleavage:
[???] Good
Color:
blue green or light green.
Hardness:
5-6 - Between Apatite and Orthoclase
Streak:
white
More details...