Jennite
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Jennite is a calcium silicate hydrate mineral of general chemical formula: Ca₉Si₆O₁₈(OH)₆·8H₂O.
Jennite occurs as an alteration mineral in metamorphosed limestone and skarn. It typically occurs as vein and open space fillings as a late mineral... Wikipedia
Color: White
Crystal class: Pinacoidal (1); (same H-M symbol)
Crystal habit: Blade shaped crystals, fibrous aggregates, platy – sheet forms
Crystal system: Triclinic