Mineralpedia Details for Giuseppettite

Named after Giuseppe Giuseppetti, a Professor of Mineralogy at the University of Pavia in Italy. Giuseppettite is a rare mineral that occurs only in Italy and Norway, and possibly in the United States. It can be found in veinlets in sanidine-rich volcanic ejecta. Associated minerals include K Feldspar, nephelie, hauyne, biotite and kalsilite.

Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/giuseppettite.pdf

Formula

Na₄₂K₁₆Ca₆Si₄₈Al₄₈O₁₉₂(SO₄)₁₀Cl₂·5H₂O 

Crystal System

Trigonal 

Crystal Habit

Anhedral Grains 

Cleavage

None, None, None 

Luster

Vitreous (Glassy) 

Color

light violet blue 

Streak

white 

Class

Trigonal - Ditrigonal Pyramidal 

Hardness

6-7 

WebMineral

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Mindat

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