Prehnite was first described as a gemstone in 1780, when it was discovered in the Karoo dolerites of Cradock, in South Africa. It was the first mineral to come from South Africa, long before this country became one of the most important gemstone producers. Today, green Prehnite originating from South Africa is also called Cape Emerald. Prehnite is named after its discoverer, Colonel Hendrick von Prehn, the German mineralogist and military officer. He was a governor of Cape of Good Hope, but was also a naturalist and stone collector. Colonel Prehn first brought Prehnite to Europe, and it became the first mineral named after a person.



Until recently, Prehnite has been a rare collector’s stone. But new findings, especially those in the Northern Territory of Australia, have made this stone more accessible. Other significant findings of Prehnite are located in China, Scotland, Mali, Namibia and the USA (New Jersey).



In China, Prehnite is sometimes called “Grape Jade” or “Putao Yu” because of its nodular crystal shape, which often resembles a raceme of grapes. Prehnite has a discrete pearlescent effect because of its pseudo chromatic colouration.


Prehnite is usually apple green in colour, although it can sometimes be seen in yellow, orange and blue. It can be light green, dark green, grey, white, or even colourless. Prehnite is clean, airy, and often large in size. Sometimes it can exhibit the so-called “cat eye effect”. Transparent forms, coming from Quebec in Canada, are faceted and smaller in size. Prehnite glows under sunlight, which makes it a very interesting stone to use in jewellery.




Prehnite is relatively hard stone, reaching 6-6.5 on the Mohs scale, which makes it suitable for high-quality jewellery production. It is sometimes classed with the zeolites, with which it is often associated. It is also found with calcite and pectolite, and occasionally with granite and gneiss, when it is frequently associated with epidote. Sometimes it is associated with native copper, such as in the Lake Superior region in North America.



Prehnite is usually processed en cabochon. Other typical cuts include oval, round and cushion shape. In some areas, you can see Prehnite in the shape of a heart, trillion and pear (or tear).





Because of its ability to glow under sunlight, Prehnite became a very interesting inspiration stone for crystal healers. It is associated with, and known to give, the capacity to connect with extraterrestrial and spiritual beings. Prehnite is considered to be a stone of Saint Raphael. It is said to be beneficial for plants and gardens, if kept in the garden.