Prehnite 13x16mm Center Drilled Faceted Pear Bead - 15-16 Inch R0911 The best available information indicates

The best available information indicates that the stone is a type of Dolomite that has been altered by volcanic activity

the inner lining (nacre) can be iridescent

keep in mind that selecting the “right” cord size is a little bit art and a little bit science

a turquoise trader and an electrical engineer

Prehnite 13x16mm Center Drilled Faceted Pear Bead - 15-16 Inch R0911 The best available information indicatesPrehnite 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.