PREHNITE
| PREHNITE | Also known as the Prediction Stone |
| Origins | Australia |
| Colours Found | Colourless, green, grey, white & yellow |
| Family | Silicate |
| Hardness | 6.00 - 6.50 |
| Refractive Index | 1.61 - 1.67 |
| Relative Density | 2.82 - 2.94 |
With its gorgeous greens and unique translucency, Prehnite is a wonderful rare exotic gem, which despite a suitable durability, has only recently gained popularity as a jewellery gemstone.
Named after the Dutch mineralogist and early governor of the “Cape of Good Hope” colony, Colonel Hendrik Von Prehn (1733-1785), who discovered it in the Cradock district of the eastern Cape province, South Africa in the early 18th century, Prehnite was the first mineral to be named after a person.
Legend and lore
Known as the “prediction stone” amongst spiritual healers, it is believed that Prehnite can enhance one’s dreaming and remembrance. Some crystal healers also believe that Prehnite’s colour and unusual touch are ideal for stress release.
Just the facts
Prehnite’s bright, almost luminescent, swirling green colours (reminiscent of Jade), mesmerizing clarity and striking lustre, make it an extremely attractive collector’s gem. In his book, “Gemstones of the World”, Walter Schumann describes Prehnite as a transparent to translucent gemstone, which accounts for its “cloudy” appearance. This is totally normal and like many gemstones, its distinctive appearance is key to its appeal. While its main colours are a range of pleasant greens that are often unique to Prehnite, yellow, grey, colourless or white varieties also exist. Prehnite has some interesting common names including “grape jade” (in China it is called “putao yu”, meaning grape jade, due to crystal formations that look like a bunch of grapes), “cape emerald” (for the location of its discovery and visual similarities to Emeralds) and “prediction stone” (see above). Prehnite is usually found in cavities along fractures of basalt. The Australian deposits occur in scattered outcrops of Antrim Plateau Volcanics of early Cambrian age (about 570 million years old) and consist of massive basalt up to 60 metres thick. Although the primary Australian deposits cover thousands of square kilometres in the east Kimberley (Western Australia) and the adjoining Northern Territory, gem quality Prehnite is very scarce. With about 90% of the world’s reserves of this beautiful green gem, most of the Prehnite you’ll see on GemsTV hails from Australia.


