Point – Prehnite #2

Prehnite is a green to yellow mineral that is used often to decorate or in jewelry. Prehnite was discovered in 1774 by the Dutch colonel Hendrik van Prehn in Zuid-Afrika and consequently named after him. It is supposedly the first mineral named after a person, but definitely not the last one. Prehnite is similar in lustre, colour and transparency, but also in origin to certain kinds of agate. It originates from hydrothermal activity: groundwater with dissolved Prehnite in it passes by a cavity where the mineral can be deposited. The Prehnite often forms in bubbly shapes or in agate-like masses. This formation is called globular or botryoidal. A unique variety of Prehnite is the material from Mali. This Prehnite often contains Epidote inclusions that are rarely found elsewhere. The Epidote in Prehnite is an important factor in determining where certain Prehnites come from.