Quartz Crystal with Analcime and (?)Pumpellyite on Matrix - NBB 193

Measurements:  60 x 53 x 42 mm

Description:  Two quartz crystals have fused together, resulting in a crystal with two perfect terminations. Two of the shaft facets are partially covered with minute analcime and (?)pumpellyite crystals. A few minute hematite specks and threads are included.

The crystals share a basalt matrix with at least two calcite crystals and small quartz crystals. 

Towards the back of the biggest crystal is a neat pressure mark, at the base of the termination ridge. At the base of the main crystal is a thin flaw. Some of the small crystals along the edges of the matrix have some damage. 

The specimen displays well on a flat surface, with the main crystal at an angle of about 50 degrees.

Weight of Specimen:  68.7 g

Chemical Composition:  SiO₂  (quartz)
                                               Ca₂MgAl₂[Si₂O₆OH][SiO₄]₂  (pumpellyite-Mg)  
                                       NaAl(Si₂O₆)•(H₂O) (analcime)
                                       CaCO₃ (calcite)

Hardness on Mohs Scale:  (quartz) 7 
                                           (pumpellyite-Mg) 5.5  
                                           (analcime) 5
                                           (calcite) 3

Location:  Brandberg, Namibia.

Specimen Code:  NBB 193

US $ 130

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