  Glauberite.  
Description from the source: 
Glauberite (Na2 Ca (SO4)2 mon.), Camp Verde District, Yavapai Co., Arizona, USA. Classic crystal cluster, usually alterated in Gips. 3,7x2,5x2 cm; 5 g. 
Source: Simone Citon 
Contributor: John Gray 
Acquired: 30 October, 2008 
Text Updated: 31 October, 2008 
Price: Trade 
Size: 1.5" 
Composition: Na2Ca(SO4)2
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