ABSTRACT

Prehnite is the first mineral discovered by Europeans in South Africa during the late 18^th century, and the first mineral named after a person, Hendrik von Prehn, who allegedly discovered the mineral specimens. The acquisition of these specimens, their type-locality, and the processes in naming prehnite involved some of the leading scientists at that time. Various names had been proposed for prehnite including rochonite, emeraud du Cap, chrysolite, oisanite, prase, chrysoprase, shorle vert du Cap, until final acceptance in 1793 as prehnite. The district of Cradock in the Eastern Cape Province, South Africa is entrenched in the literature as the location of von Prehn’s specimens, yet no documentary evidence exists to support this claim. In contrast, several other prehnite occurrences are known from further inland, hosted in similar geological environments to those in the Cradock district, and it is concluded that the type-specimens came from one of these hinterland locations, within the Karoo Basin of South Africa.