Description: This is a interesting prehnite specimen from Morocco, specimen wide around 11cm, green prehnite sphere wide around 4.9cm, on an ophitic matrix covered with small crystals of dark colored Ferro-actinolite and lighter colored Epidote. This mineral be Named in 1788 in honor of the Dutch Colonel, Hendrik von/van Prehn, who was a governor of Cape of Good Hope, and a naturalist and mineral collector, he discovered the mineral in 1774 at the Cape of Good Hope in South Africa.