RARE Rosartita, Gold Slag, Long Rectangle Shaped Cabochon (46x13mm) 

Deep Red with some varying color striations

Rosarita. This was more commonly called "Gold Slag." This stone was a result of the early gold mining days. The stone looks like slag glass, but gets it's red color from the gold byproducts.

It is a unique by-product of the1960s and 1970s gold refining processes.