Introduction: Prehnite was the first mineral to be named after a person, notably Hendrik Prehn 1733-1785). It occurs in certain lavas, such as basalts as it is a low temperature mineral
Distribution: West of the Brandberg in Copper Valley, Tubussis and the Karasberg District.
Composition: Silicate
Crystal system: Orthorhombic
Lustre: Pearly, vitreous
Streak: White
Hardness: 6-6.5