Prehnite is a lovely pastel green coloured stone. It's often found with distinctive black inclusions which may be the mineral epidote, tourmaline or an amphibole.
It can be very difficult to identify some mineral inclusions without carrying out in depth analysis. This is not always possible or practical for any number of reasons.
These prehnite crystals are mostly inclusion free which is why they're classed as a grade A stone.
Prehnite was first discovered in the Cape of Good Hope by Dutchman Hendrik von Prehn. Governor of the Cape of Good Hope and an avid mineral collector, he's believed to have been the first person to have imported prehnite to Europe.
The stone was named in his honour three years after he died in 1788.
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. It occurs in veins and cavities of certain volcanic rocks.
Prehnite can be found in several countries around the world including the United Kingdom. Large quantities of gem grade material comes from the Northern Territories in Australia.
Our grade A prehnite crystals are size medium. Size can vary from piece to piece.