In China Prehnite is known as 'Grapestone'.

Our prehnite is possibly the finest quality gem grade prehnite in the world and the only mine producing yellow prehnite.

Prehnite is a phyllosilicate of calcium and aluminium. Fe³⁺ may substitute aluminium in the structure.

Prehnite Characteristics:

Composition: Ca₂Al(AlSi₃O10₁₀)(OH)₂
Crystal System: Orthorhombic
Hardness: 6 - 6.5
Specific Gravity: 2.80 - 2.90
Brittle as displayed by most glass-like minerals.
Fracture: Cleavage: Distinct.
Streak: Colourless
Lustre: Vitreous to pearly.
Colour: Colourless to all shades of green, yellow and rarely dark yellow
Luminescence: Fluorescent SW Blue
Diaphaneity: Translucent to sub-transparent
Habit: Globular, reniform, sometimes stalactitic.

Prehnite is the first mineral to be named after a person. Prehnite was first described in 1989 and named after a dutch Colonel Hendrik Von Prehn (1733-1785) commander of the military forces of the Dutch colony at the Cape of Good Hope. Prehnite often occurs with zeolites and is mistakenly referred to as a zeolite.

Prehnite is found in many countries worldwide but gem grade prehnite is rare. Prehnite was discovered in the Wave Hill area of Northern Territory many years ago and during the 1960s, several fossickers sold a few Kgs of low to medium grade material to dealers in Victoria. These first shipments of prehnite were sent to Germany for carving but nothing more was mined after those early shipments.

During the 1970s, Gerald Pauley had the good fortune to gain permission to access old mine reports at the Bureau of Mineral Resources in Darwin, prior to it being blown away by Cyclone 'Tracey'. He discovered articles about various gemstones near Wave Hill.

On the first trip to Wave Hill, in 1974, he realised the potential of the area to produce fine quality prehnite and also identified other gem and mineral reserves of possible economic significance; namely: Agate, Amethyst, Smoky Quartz and Red Jasper (Chicken Blood Jasper).

After years of prospecting the area, in the early 1980's he discovered what is believed to be the finest deposit of gem grade prehnite in the world.

In March 2013, Linna Huang purchased the almost 10 Sq. Kilometre lease and commenced the first full scale mining operation on the reserve.

Over the years since the 1980s surface collecting produced a few Kgs of high grade prehnite but after years of fossicking and hand collecting the surface deposits were depleted. By observation, surface material is highly crazed and faded due to the hostile extremes of temperature in the semi-desert area where the lease is situated. Daytime temperatures in the desert area can be as high as 35º C but at night it can freeze. This cause the prehnite to fracture and, since the early discovery of the gem grade prehnite in the early 1980's, no-one has seen true high grade prehnite.

Heavy earth moving equipment was brought in to open, and prove, the deposit. The results were outstanding with the best quality prehnite ever seen being uncovered a few centimetres below the surface. A further 10 centimetres down harder basalt was encountered and the equipment failed to be effective in ripping the basalt efficiently. Prehnite was found in the harder basalt but it will have to wait until the next mining season. After cleaning a few tonnes of the mined material we were excited too see the quality.

This fine prehnite will soon be available commercially on the international market as high gem grade rough and as cut stone and in jewellery.

Prehnite Metaphysical Properties