General Information:
Chemical Formula:
Ca2B6O11·5(H2O)
Composition:
(Molecular Weight = 205.54 gm)
Calcium 19.50 % Ca
Boron 15.78 % B
Hydrogen 2.45 % H
Oxygen 62.27 % O
Empirical Formula:
Ca(B3O4)(OH)3·(H2O)
Environment:
Lacusterine limestone hosted borate deposits.
Locality:
Furnace Creek district, Death Valley, Inyo Co. California.
Name Origin:
After William T. Coleman, owner of the Death Valley, California mine where this species was first found.
Physical Properties:
Cleavage:
[010] Perfect, [001] Distinct
Color:
colorless, gray, gray white, yellowish white, or white.
Density:
2.42
Diaphaniety:
Transparent to translucent
Habits:
Blocky - Crystal shape tends to be equant (e.g. feldspars)., Crystalline - Coarse - Occurs as well-formed coarse sized crystals., Massive - Granular - Common texture observed in grani te and other igneous rock.
Hardness:
4.5 - Between Fluorite and Apatite
Luminescence:
None.
Luster:
Vitreous (Glassy)
Streak:
white
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