General Information:
Chemical Formula:NaCa2(Mg,Fe++)4Al(Si6Al2)O22(OH)2
Composition:(Molecular Weight = 867.37 gm)Sodium 2.65 %
NaCalcium 9.24 %
CaMagnesium 8.41 %
MgAluminum 9.33 %
AlIron 6.44 %
FeSilicon 19.43 %
SiHydrogen 0.23 %
H Oxygen 44.27 %
O Empirical Formula: NaCa2Mg3Fe2+Si6Al3O22(OH)2
IMA Status:Approved IMA 1978
Locality:Pargas, Finland.
Name Origin:Named after its locality.
Physical Properties: Cleavage:[110] Perfect, [010] Perfect
Color:bluish green, brown, grayish black, light brown, or dark green.
Density:3.069 - 3.181, Average = 3.12
Diaphaniety:Transparent to translucent
Habits:Tabular - Form dimensions are thin in one direction., ,
Hardness:6 - Orthoclase
Luster:Vitreous (Glassy)
Streak:white
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