Prehnite Natural 8mm Bicone Faceted - 15-16 Inch Gemstone Green is the most common

Green is the most common color for Aventurine

Azurite in crystal form is extremely rare and expensive

the month the ancient Romans dedicated to Neptune

occasionally mingled with rust-brown

Most commonly mined in Madagascar

Prehnite Natural 8mm Bicone Faceted - 15-16 Inch Gemstone Green is the most commonPrehnite 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.