Smoky Quartz, Feldspar and Schorl on Matrix - NAM 018

Measurements:  91 x 75 x 26 mm 

Description:  Small smoky quartz and schorl crystals with feldspar, on a conglomorate matrix. 

Some of the crystals have small nicks. A few bits of stubborn orangy-brown clay are attached to the specimen.

Weight of Specimen:  164.2  g 

Chemical Composition:  SiO₂ (quartz)
                                      NaFe²⁺₃Al₆Si₆O₁₈(BO₃)₃(OH)₄  (schorl)
                                       KAlSi₃O₈ (feldspar)

Hardness on Mohs Scale:  SiO₂ (quartz)  7 
                                          (schorl)  7.5     
                                           (feldspar) 6 - 6.5

Location:  Erongo Mountains, Erongo Region, Namibia.

Specimen Code:  NAM 018

R 250