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PREHNITE
Wave Hill, Northern Territory, AUSTRALIA

Prehnite from Wave Hill, Northern Territory
is possibly the finest quality gem grade prehnite in the world.
Prehnite is a phyllosilicate of calcium and aluminium.
Fe3+ may substitute aluminium in the structure.

Prehnite Characteristics:

Composition: Ca2Al(AlSi3O10)(OH)2
Crystal System: Orthorhombic
Hardness: 6 - 6.5
Specific Gravity: 2.80 - 2.90
Fracture: Brittle as displayed
by most glass-like minerals.
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, a unique and beautiful gem, is found on our Mineral Lease at Wave Hill, Northern Territory, Australia. Our Lease produces the world’s best prehnite.
Our workshop in Victoria produces cabochons, polished slices and tumbled stones. Prehnite occurs in varieties of green and yellow and in rare case may be a deep yellow to almost gold colour.

At the dawn of the Cambrian Era, over 530 million years ago, many parts of Australia were engulfed by lava from active volcanoes. One area in the north witnessed the largest flow of volcanic lava recorded in Australia, covering an area of 250,000 Square Kilometres to a depth of up to 1,000 metres. SunJade® subsequently formed inside gas bubbles within the cooling lava. Known as The Antrim Plateau Volcanics, it is the largest flood basalt province in Australia and outcrops in numerous places in the Northern Territory.

During a trip to the Northern Territory in 1974, Gerald Pauley visited the Bureau of Mineral Resources in Darwin to search through old geological survey reports. In those reports he discovered a reference to outcrops of gemstones in the Wave Hill area of Northern Territory, Australia, some 800 kilometres south south west of Darwin. Armed with this knowledge he embarked on numerous field trips to the area and in the early 1980's he discovered what is now believed to be the largest deposit of facet grade prehnite in the world.

During a field trip to the area, one of the team members, upon cracking open a chunk of basalt exposed a nodule of deep yellow prehnite and exclaimed,
"Oh, it looks just like bottled sunlight."
From this statement the name, SunJade® was born to describe this beautiful gem variety of prehnite.

After experimentation with cutting techniques the correct orientation and dimensions were discovered to gain the best visual effect from this rare and unique gemstone. SunJade® has an unusual characteristic of capturing light and creating spectacular visual effects similar to 'Moonstone' and 'Cat's Eye' gems but with an uncanny, almost neon or luminous, glow.

SunJade® is a versatile gemstone. In the past, gems were categorised as precious and semiprecious but current high market values of all gems have made these old terms completely obsolete. Price is a function of rarity, and high grade SunJade® is extremely rare. Lesser quality grades of gemstones are categorised as ornamental stone and these materials also have a wide variety of applications. Decorative articles for personal adornment, carvings, and ornaments, as well as more adventurous products, such as tiles and even bench tops, are possible products that can be made from this beautiful gemstone. SunJade® is tough enough to make delicate carvings and, when suitably transparent, can also be faceted for use in gold and silver jewellery.

We are only just beginning to see the exceptional potential of this wonderful stone and as we design new and exciting jewellery, SunJade® will gain acclaim on the international market as well as in Australia. 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. The best prehnite in the world is to be found in th Antrim Plateau Volcanics. Prehnite was first 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, Gerald Pauley 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 mid 1980’s, Gerald discovered what is believed to be the finest deposit of gem grade prehnite in the world.During a field trip to the area in the 1980's one of the team, upon cracking open a piece of basalt revealing a small nodule of prehnite exclaimed:
"Oh! it looks just like Bottled Sunlight."

And so the Registered Tradename SunJade® was coined. 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 1980's 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 during the winter months, in the desert area, can be as high as 35°C but at night it can freeze. This causes the prehnite to fracture and since the 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.
Blasting is not an option as it will cause fractures in the gem quality material. Prehnite was found in the harder basalt but it will have to wait until future mining seasons. After cleaning a few tonnes of the mined material we were excited to see the quality, colour and clarity of the material. The prehnite found in the basalt was a very dark green colour as it had been shielded from the extreme weather conditions in this outback, desert area. This fine prehnite is now available commercially on the international market as high gem grade rough and as cabochons and in jewellery.

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