Schorl / Black Tourmaline Crystal on Feldspar Crystal – VAR 040

Measurements:  33 x 25 x 22 mm 

Description:  A well-formed schorl crystal pair (main crystal 14 mm long) sits on / is partially embedded in a lovely, well-formed floater feldspar crystal, that has some traces of mica on its surface, giving it a few shiny patches. 

The specimen displays well on a flat surface, in a number of positions. The image (bottom left) shows one of the sides of the feldspar crystal.

The schorl crystals are not terminated, and has only a few small nicks (easily seen on these images). 

Weight of Specimen:  22.9 g 

Chemical Composition:  NaFe²⁺₃Al₆Si₆O₁₈(BO₃)₃(OH)₄  (schorl)
                                       KAlSi₃O₈  (feldspar) 
                                        KAl₂(Si₃Al)O₁₀(OH_,F)₂  (muscovite)

Hardness on Mohs Scale:  (schorl /  black tourmaline)  7.5
                                          (feldspar)  6 - 6.5
                                          (muscovite)  2 - 2.5

Location:  Zimbabwe, Africa. 

Specimen Code:  VAR 040

US $ 25