Excellent intensive blue and gemmy crystals of haüyne in a vug of a sanidinite ejection block.

Formula: Na3Ca(Si3Al3)O12(SO4)
System: Isometric
Colour: Blue, white, grey, ...
Lustre: Vitreous, Greasy
Hardness: 5½ - 6

Locality: In den Dellen quarries, Niedermendig, Mendig, Laach lake volcanic complex, Eifel, Rhineland-Palatinate, Germany

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