This Specimen has been sold.
3.2" Botryoidal Prehnite Cluster - Mali
This is a 3.2" wide association of translucent, botryoidal green prehnite collected from the Kayes Region of Mali, Africa.
Prehnite is a calcium aluminum silicate with the chemical composition Ca2Al(AlSi3O10)(OH)2. It generally occurs as volcanic cavity infillings. It often displays colors between yellow and green, but colorless and blue specimens are not unheard of.
Epidote is a green silicate mineral that is commonly found in regionally metamorphosed rocks. It often forms lustrous, elongated, and interconnected crystals that are highly coveted by collectors. While nearly all epidote is green, it may take on many different shades and tones from yellowish to deep green.