Hyalite Opal, Fluorite and Schorl - NAM 012

Measurements:  78 x 45 x 38 mm 

Description:  A group of schorl (variety foitite) and fluorite crystals, with a capping of hyalite opal and bits of mica on some surfaces.

The specimen, which has relatively little damage, should fluoresce beautifully under ultraviolet light. 

Weight of Specimen:  122.4 g

Chemical Composition: CaF₂ (fluorite) 
                                       NaFe²⁺₃Al₆Si₆O₁₈(BO₃)₃(OH)₄  (schorl)
                                       SiO₂•1.5(H₂O) (basic opal)  
                                       KAl₂(Si₃Al)O₁₀(OH_,F)₂ (muscovite)

Hardness on Mohs Scale:  (fluorite)  4
                                          (schorl) 7.5
                                          (basic opal)  5.5 - 6 
                                          (muscovite)  2-2.5

Location:  Erongo Mountains, Erongo Region, Namibia.

Specimen Code:  NAM 012

R 450