General Information:
Chemical Formula:
Ca5(SiO4,SO4)3(OH,Cl,F)
Composition:
(Molecular Weight = 505.35 gm)
Calcium 39.65 % Ca
Silicon 8.34 % Si
Hydrogen 0.12 % H
Sulfur 9.52 % S
Chlorine 2.10 % Cl
Oxygen 39.89 % O
Fluorine 0.38 % F
Empirical Formula:
Ca5(SiO4)1.5(SO4)1.5(OH)0.6Cl0.3F0.1
Environment:
In a skarn.
IMA Status:
Approved IMA 1971
Locality:
Chichibu mine, Saitama Prefecture, Japan.
Name Origin:
Named for the composition and Reuben B. Ellestad (1900-1993), Amierican analytical chemist of Minneapolis, Minnesota, USA.
Physical Properties:
Color:
light pink, purple gray, or pink.
Density:
3.02
Diaphaniety:
Translucent
Habits:
Anhedral Grains - Granular minerals without the expression of crystal shapes, Massive - Uniformly indistinguishable crystals forming large masses.,
Hardness:
4.5 - Between Fluorite and Apatite
Luster:
Vitreous (Glassy)
Streak:
beige
More details...