Smoky Quartz, Hyalite Opal and Schorl – NER 007

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Measurements:  48 x 37 x 27 mm

Description:  A smoky quartz crystal with a few smaller smoky quartz crystals and some (mostly damaged) schorl crystals attached to its base.

The main feature of this specimen, is patches of light green, gemmy hyalite opal crystals that sit on (mostly) two faces of the main crystal.

The main quartz crystal appears to be undamaged, but the lesser quartz crystals have some nicks and pressure marks.

Weight of Specimen:  32.7 g

Chemical Composition:   SiO₂•1.5(H₂O)  (opal)  
                                    SiO₂  (quartz) 
                                    NaFe²⁺₃Al₆Si₆O₁₈(BO₃)₃(OH)₄  (schorl) 

Hardness on Mohs Scale:  (opal)  5.5-6     
                                      (quartz)  7   
                                      (schorl)  7.5   
                                              
Location:  Erongo Mountains, Erongo Region, Namibia.