Hyalite Opal on Conglomorate Matrix - NER 064 

Measurements:  82 x 74 x 35 mm 

Description:  Hyalite opal with an excellent colour quality, that fluoresces beautifully under ultraviolet light, sits on a conglomorate matrix of schorl, feldspar and quartz. The bottom of the specimen has several small schorl and quartz crystals, as well as one very small patch of hyalite opal.

There is some damage to the edges of the specimen.

Chemical Composition:  SiO₂•1.5(H₂O)  (opal)
                                       NaFe²⁺₃Al₆Si₆O₁₈(BO₃)₃(OH)₄  (schorl)                                                KAlSi₃O₈  (feldspar)
                                       SiO₂  (quartz)

Hardness on Mohs Scale:  (opal)  5.5-6 
                                         (schorl )  7.5                                                                                       (feldspar)  6 - 6.5   
                                         (quartz)  7            

Location:  Erongo, Namibia.

Specimen Code:  NER 064