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Jade is a precious stone that has been used in ornaments, tools, and weapons for thousands of years. It is a tough material that is commonly carved to make jewellery, urns, vases, and statues. Jade is found in rocks formed under high pressure and is composed of two minerals: jadeite and nephrite. While jadeite is found in Myanmar, New Zealand, Canada, Taiwan, Guyana, Southern Europe, Russia, and China, nephrite is found in Australia. Here is an overview of where nephrite jade is found in Australia.
| Characteristics | Values |
|---|---|
| Types of Jade | Jadeite, Nephrite |
| Jadeite Found in Australia? | No |
| Nephrite Found in Australia? | Yes |
| Nephrite Locations in Australia | Cowell, South Australia; Tamworth, New South Wales; Heemskirk Falls Prospect, Tasmania |
| Nephrite Colours | Deep Green to Black, Lighter Shades |
| Other Names for Nephrite Jade | Australian Black Jade, Mutton Fat Jade |
| Nephrite Composition | Magnesium Iron Calcium Silicate |
| Nephrite Crystal Structure | Microcrystalline |
| Mining Techniques | Excavators in Open Pits, Diamond-tipped Core Drills, Hydraulic Spreaders, Water-cooled Diamond Saws |
| Uses | Jewellery, Ornaments, Tools, Weapons |
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What You'll Learn
Jade deposits in Australia
Jade is a term that covers two different minerals: jadeite and nephrite. Jadeite is considered the most important and rare type of jade, known for its rich, green colour. It is a sodium alumino-silicate formed under high pressure deep within the Earth. On the other hand, nephrite is a magnesium iron calcium silicate, with iron as the colouring agent. Nephrite is tougher than diamonds and is found in metamorphic rocks formed in current or ancient subduction zones.
In Australia, nephrite is the only type of jade found. The largest deposit of nephrite jade in Australia is in Cowell, South Australia, discovered in 1965. This deposit is also considered one of the largest in the world. The Cowell deposit is mined in open pits, with large boulders containing the jade extracted using excavators. The jade is then exposed using diamond-tipped core drills and broken off using hydraulic spreaders. It is then cut and polished for use in jewellery, ornaments, and other decorative items.
There are two other known nephrite jade deposits in Australia, both much smaller than the Cowell deposit. One is located near Tamworth, New South Wales, and the other is at Heemskirk Falls Prospect in Tasmania, discovered in 2015. There have also been unconfirmed reports of nephrite jade occurrences in the Pilbara region of Western Australia. However, it is important to note that while there are mines of ornamental stones marketed as jade in this region, they are not true jades.
The nephrite jade found in Australia is known as Australian Black Jade and is highly sought-after due to its beauty, rarity, and ability to take on a high polish. It combines deep blacks with a medium to fine grain, resulting in a mirror-like shine when optimally cut and polished. Australian Black Jade is exported worldwide, with a significant portion going to Asia and other countries such as Germany, Italy, the USA, Canada, and New Zealand.
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Cowell, South Australia
Cowell, a town on the Eyre Peninsula in South Australia, is home to one of the world's largest deposits of nephrite jade. This deposit was discovered in 1965 when Harry Schiller, a local farmer, found a 3-4 kg boulder of dense, hard nephrite near an outcrop of white marble.
The Cowell Jade Province, as it is known, covers several kilometres and features numerous visible outcrops of nephrite jade. This variety of jade is a metamorphic stone, formed through changes in heat and pressure, as well as the correct ratio of calcium, iron, magnesium, silicate, and water. Over time, the mountain-building process led to the formation of veins, lenses, and pods of nephrite jade in the Cowell region.
The jade bodies at Cowell are typically elongated and lens-shaped, found within host rocks such as dolomitic marble and banded calc-silicate. These high-grade jade deposits are estimated to have formed around 1840 million years ago. Cowell jade exhibits a range of colours and textures, from grey to dark green, and even dense black hues. Three main varieties are marketed: green nephrite, black nephrite, and premium black nephrite.
Cowell is currently the only commercial jade mine in Australia, with mining operations utilising excavators and open pits. The extracted jade is then cut, polished, and graded according to colour and quality. The toughness of jade makes this process challenging, requiring the use of water-cooled diamond saws and drills. The jade produced at Cowell is exported worldwide, with significant exports to Asia, Germany, Italy, the USA, and Canada.
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Tamworth, New South Wales
But Tamworth is also known for being a source of nephrite jade in Australia. Between 1977 and 1996, small mining ventures around Tamworth produced about 600 kg of nephrite. Tamworth nephrite is generally lighter in colour than the material found in Cowell, South Australia, the country's largest jade deposit.
There are two minerals that are commonly called jade: nephrite and jadeite. The traditional Chinese jade is nephrite. In New Zealand, jade is called pounamu or greenstone. As one of the world's oldest decorative stones, jade has been prized for its beauty across the world. The two jade minerals, nephrite and jadeite, are both tough and have small granular crystals giving a fibrous appearance. They have quite different chemical compositions and structures. Nephrite can be white, yellow, green, and brown to black, depending on the amount of iron and magnesium in the mineral. Jadeite can be green, pink, purple, brown, and white.
Nephrite jade is very tough—the toughest known natural mineral. It is three times tougher than ceramics and even tougher than steel. Its fibrous, interlocking structure gives nephrite its inherent toughness and enables it to take on a high polish.
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Heemskirk Falls Prospect, Tasmania
Jade is a tough material that has been used to make ornaments, tools, and weapons for thousands of years. It is also used in jewellery, statues, and urns. Jade is a term that covers two different minerals: jadeite and nephrite. Of these two, only nephrite jade is found in Australia.
Heemskirk Falls Prospect, in Tasmania, is one of the three deposits of nephrite jade in Australia. The other two are Cowell in South Australia and Tamworth in New South Wales. Heemskirk Falls Prospect was discovered in 2015. The area is named after Mount Heemskirk, a mountain in Western Tasmania, west of the West Coast Range. The mountain was named by George Bass and Matthew Flinders during their circumnavigation of Tasmania between 1798 and 1799. The mountain's indigenous Peerapper name is recorded as Roeinrim or Traoota munatta.
Heemskirk Falls is a waterfall that has mostly been lost due to the construction of dams and irrigation systems, which caused the region to flood and become Lake Pieman. However, the upper section of Heemskirk Falls still exists and flows directly into Lake Pieman. The waterfall is incredibly difficult to access by foot, as the tracks are overgrown and the bush is very dense. It is possible to see the waterfall from upstream, but the river becomes too wide and deep above the falls to allow further access.
Nephrite jade is a magnesium iron calcium silicate, with iron as the colouring agent. A high iron content results in deep green to black colours, while a low iron content leads to lighter shades. Nephrite is a popular name given to gem-quality tremolite, one of the amphibole groups of minerals. These minerals have elongated, fibrous crystals, and this fibrous, interlocking structure gives nephrite its toughness and ability to take on a high polish.
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Jade mining in Australia
Jade is a term that covers two mineral types: jadeite and nephrite. Jadeite is considered "true jade" or "precious jade". It is a sodium alumino-silicate formed under high pressure deep within the Earth. Nephrite, on the other hand, is a magnesium iron calcium silicate. It is a common component of greenschist and amphibolite facies rocks. It is also found in metamorphic rocks, formed in current or ancient subduction zones.
In Australia, nephrite is the only type of jade found. The largest deposit of nephrite jade in Australia is found at Cowell, in South Australia. It was discovered in 1965 by a local farmer who found a 3-4 kg boulder of nephrite near an outcrop of white marble. There are over 100 occurrences of nephrite jade within an area of about 10 km2 at Cowell. These rocks originally contained about 80,000 tonnes of nephrite.
There are two other nephrite jade deposits in Australia: one near Tamworth, New South Wales, and another at Heemskirk Falls Prospect, Tasmania. The Tamworth deposit was discovered in 1978 and small mining ventures in the area produced about 600 kg of nephrite between 1977 and 1996. The deposit at Heemskirk Falls Prospect was discovered more recently, in 2015.
Mining nephrite jade is a complex process due to the toughness of the material. At Cowell, mining is done using excavators in open pits. Large boulders containing jade are extracted from the ground and jade is exposed using diamond-tipped core drills. Hydraulic spreaders are then pushed into the rock so that the jade can be broken off. The jade is then transported by trucks for sawing and grading according to colour and quality. It is then cut and polished.
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Frequently asked questions
Jade is a tough, microcrystalline material that is commonly used to make jewellery, ornaments, urns, vases, and statues. It is the trade name for two different gem materials: jadeite and nephrite.
In Australia, nephrite jade is found in Cowell, South Australia, Tamworth, New South Wales, and Heemskirk Falls Prospect, Tasmania. Cowell is currently the only commercial jade mine in Australia.
Australian Black Jade, also known as Australian Nephrite Jade, combines signature blacks with a medium to fine grain, affording a very high, mirror-like polish.
Australian jade is used for jewellery and ornamental carvings.
Yes, jade is found in other parts of the world, including Myanmar, New Zealand, Canada, Taiwan, Russia, China, Guatemala, Japan, Kazakhstan, the USA, and Europe.
