Prehnite 7x10mm Faceted Tube - 15-16 Inch Stone Type_Ruby Zoisite which make the shells attractive

which make the shells attractive as decorative objects

A cryptocrystalline Chalcedony

but blends it with browns

It is named for the Amazon River in Brazil

Prehnite 7x10mm Faceted Tube - 15-16 Inch Stone Type_Ruby Zoisite which make the shells attractivePrehnite 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.