Blackjack Gem!! Fabulous Rare Rough Natural Translucent Sphalerite 925 Silver Pendant from Spain - 1.0" - 5.37 Grams

Very rare rough natural translucent yellowish to honey brown Sphalerite 925 silver pendant from Spain.
Sphalerite is a zinc sulfide mineral with a chemical composition of (Zn,Fe)S. Sphalerite is the major ore of zinc.
Names for sphalerite used in the past or by miners include "zinc blende," "blackjack," "steel jack," and "rosin jack."
Sphalerite has an incredible dispersion of 0.156 that exceeds that of all of the popular gems and is three times higher than the dispersion of diamond (0.044).
Sphalerite is a difficult stone to cut and polish, that's why this pendant is even more interesting.
Sphalerite is untreated and not enhanced.
Location: Las Manforas Mine (Aliva Mine), Camaleño, Cantabria, Spain
Size: 2.7 x 1.4 x 1.4 Centimetres with Bail
Weight: 5.37 Grams Combined