General Information:
Chemical Formula:
(Mg,Fe++)3Si2O5(OH)4
Composition:
(Molecular Weight = 300.77 gm)
Magnesium 18.18 % Mg
Iron 13.93 % Fe
Silicon 18.68 % Si
Hydrogen 1.34 % H
Oxygen 47.88 % O
Empirical Formula:
Mg2.25Fe2+0.75(Si2O5)(OH)4
IMA Status:
Approved IMA 1962
Locality:
Antigorio, Italy
Name Origin:
Named after its locality. From the Latin, serpens - "snake."
Physical Properties:
Cleavage:
[001] Good
Color:
green, gray, bluish gray, brown, or black.
Density:
2.5 - 2.6, Average = 2.54
Diaphaniety:
Translucent to Subopaque
Habits:
Platy - Sheet forms (e.g. micas)., Massive - Uniformly indistinguishable crystals forming large masses., Scaly - Morphology like fish scales.
Hardness:
3.5-4 - Copper Penny-Flourite
Luster:
Vitreous - Greasy
Streak:
greenish white
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