General Information:
Chemical Formula:Na(Al,Fe+++)Si2O6
Composition:(Molecular Weight = 202.14 gm)Sodium 11.37 %
NaAluminum 13.35 %
AlSilicon 27.79 %
SiOxygen 47.49 %
O Empirical Formula: NaAl(Si2O6)
Environment:Strongly metamorphosed sodium-rich serpentinous rocks
IMA Status:Approved IMA 1987
Locality:Clear Creek, San Benito County, California. Near Tawmaw and Hpakan villages, Upper Burma.
Name Origin:From the Spanish, piedra de ijada, "stone of the side," because its supposed to cure kidney ailments if applied to the side of the body.
Physical Properties: Cleavage:[110] Good
Color:green, white, pale bluish gray, grayish green, or pale purple.
Density:3.25 - 3.35, Average = 3.3
Diaphaniety:Translucent to subtranslucent
Habits:Granular - Generally occurs as anhedral to subhedral crystals in matrix., Fibrous - Crystals made up of fibers., Massive - Fibrous - Distinctly fibrous fine-grained forms.
Hardness:6.5 - Pyrite
Luminescence:Non-fluorescent.
Luster:Vitreous (Glassy)
Streak:white
More details...
