Group of Prehnite, Calcite and Quartz Crystals - NBB 111

Measurements:  28 x 25 x 15 mm

Description:  A lovely group of gemmy, bladed prehnite crystals with calcite crystals and one small, clear quartz crystal. The specimen has quite a few black specks, possibly hematite.

The calcite crystals have some damage, but the prehnite only has damage where it parted from its matrix.

Weight of Specimen:   13.3 g

Chemical Composition:   Ca₂Al₂Si₃O₁₀(OH)₂   (prehnite)
                                        SiO₂   (quartz)  
                                        CaCO₃  (calcite)

Hardness on Mohs Scale:   (prehnite)  6-6.5
                                           (quartz)  7  
                                           (calcite)  3

Location:  Brandberg, Namibia. 

Specimen Code:  NBB 111

US $ 45