PREHNITE
Prehnite is a calcium hydroxy-aluminosilicate mineral
(Ca2Al(AlSi3O10)(OH)2). It
tends to be a cavity-filling mineral in some extrusive igneous rocks
(lavas). It’s typically pale green in color and tends to form bulbous or
somewhat rounded crystal masses (reniform).
Prehnite
(4.9 cm across)
Prehnite
(greenish) associated with quartz & calcite & babbingtonite from
Westfield, Massachusetts, USA.
(Wayne State University collection, Detroit, Michigan,
USA)
Prehnite
(greenish) from the Kayes region, Mali.