Prehnite on Calcite, on Basalt - NBB 068

Measurements:  70 x 41 x 27 mm

Description:  Aggregates of light green prehnite crystals on calcite, with a few small quartz crystals. All rest on a basalt matrix. 

Damage to the specimen appears to be confined to the edges.

Weight of Specimen:  80.5 g

Chemical Composition:   Ca₂Al₂Si₃O₁₀(OH)₂   (prehnite)  
                                       CaCO₃  (calcite)
                                       SiO₂  (quartz)  
                                                                         
Hardness on Mohs Scale:   (prehnite) 6-6.5
                                           (calcite)  3 
                                           (quartz)  7   

Location:  Brandberg, Namibia.

Specimen Code:  NBB 068

US $ SOLD