The most striking characteristic of the mineral prehnite is the stone's delicate pastel green colour. These tumbled stones which come from Namibia were carefully selected during one of our many trips to South Africa.
The mineral prehnite was first discovered in the Cape of Good Hope by Dutchman Hendrik von Prehn. The governor of the Cape of Good Hope and an avid mineral collector, Prehn is believed to have been the first person to have imported the newly found stone to Europe. It was named in his honour in 1788 three years after he died.
Prehnite is believed to be the first mineral to have been named after a person. It's also believed to have been the first mineral to be described from South Africa. At that time the country was not known for its rich mineral reserves.
Although brittle, prehnite is a relatively hard stone that grades 6 to 6.5 on Mohs scale of mineral hardness. It occurs in veins and cavities of certain volcanic rocks and can be found in several countries around the world including the United Kingdom. Large quantities of gem grade prehnite come from the Northern Territories in Australia.
These prehnite tumbled stones are a small to medium size. Weights and sizes do vary slightly from piece to piece. In this size we only have a very limited number of stones left available.