Prehnite 13x16mm Center Drilled Faceted Pear Bead - 15-16 Inch Stringing Material This turquoise is known for

This turquoise is known for having a higher silica content than many other types

Topaz obtains much of its popularity from its beautiful colors and its status as a birthstone

Natural magnesite stones are usually white with a dark web-like pattern

a Greek philosopher and botanist who also named the stone

violet or indigo

Prehnite 13x16mm Center Drilled Faceted Pear Bead - 15-16 Inch Stringing Material This turquoise is known forPrehnite 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.