Prehnite Natural 8mm Bicone Faceted - 15-16 Inch Gemstone occasionally mingled with rust-brown

occasionally mingled with rust-brown

Most commonly mined in Madagascar

the month the ancient Romans dedicated to Neptune

the resulting rock is dark gray to deep black in color and riddled with pits and holes where air was trapped in the stone

It is a variety of banded Chalcedony with layers that may contain scarlet

Prehnite Natural 8mm Bicone Faceted - 15-16 Inch Gemstone occasionally mingled with rust-brownPrehnite was the first mineral to be named after a person: its discoverer, Dutch Colonel Hendrik Von Prehn. Von Prehn discovered the stone in South Africa in 1774. Prehnite is translucent to transparent, in colors from light green to yellow green to olive, with occasional inclusions of Black Tourmaline that crisscross the stone in fibrous patterns. It is a phyllosilicate composed of silicon, calcium and aluminum with trace amounts of iron.