Gemstones from Australia

Opal

Back in 1839, extraordinary geologist and mineralogist, Johannes Menge discovered some common opal in South Australia and from this inauspicious beginning we have arrived today where 90 to 95% of all the opals in the world come from Australia.

Johannes Menge was a very interesting man who we need to thank not only for the launch of the opal mining industry but also the fine wines of the Barossa Valley, as he was the man who recognized the area's potential for viticulture.

It was not until major finds of precious opals were made in the late 1800s and early 1900s that things really took off for the Australian mining industry. At this point the Europeans recognized their quality and began to buy them in serious quantities.

Around 100 million years ago, there was a massive shallow sea in what is now central Australia. This ocean provided the water and minerals needed to create the opals that can now found on what were the shores of this body of water.

• Boulder Opals to the north
• Black Opals in the east
• White Opals in the south

Mining is never an easy profession but digging for precious gems in the deserts and mountains of outback Australia is very tough indeed. Some of the world's finest opals are found in a number of famous mining sites situated in very inhospitable surroundings.

• Mintabie, Coober Pedy and Andamooka in South Australia
• White Cliffs and Lightning Ridge in New South Wales
• Winton and Quilpie in Queensland

Opals are Australia's national gemstone and although they are rated fairly low on Moh's hardness scale at 5.5 – 6.5 this number can be deceptive.

Boulder opals, black opals and varieties such as opals-in-matrix, Koroit opals and Yowah nuts are still connected to the rock in which they formed so are often much tougher than you might think.

In other circumstances, thin strips of precious opal are attached to a solid backing material (Opal Doublets) or sometimes given a protective crystal dome cover (Triplets) which again makes them durable enough for all types of jewelry.

Sapphire

It might come as a surprise but Australia has been a major source of sapphires for quite some time with very productive mines found in northern New South Wales and central Queensland.

Most of the sapphires found in Australia are blue but green and yellow examples have also been found. They are often quite dark in color but with a little heat treatment turn into gorgeous bright gemstones.

A couple of decades ago, Australia provided around 70% of the world's sapphires but this has dropped considerably as other countries are able to mine for these gemstones much more economically. Australian mining companies have to adhere (quite correctly) to strict environmental and labor laws.

Sapphire is a form of the mineral corundum. If they are any color other than red then they are called sapphires, if they are red then they are rubies. Australian rubies are rare but can be found in mines close to the sources of sapphires.

Diamond

Australia has huge deposits of diamonds, however most are for industrial uses. The famous Argyle mines of Western Australia has produced top quality pink, champagne and cognac diamonds for decades but is unfortunately in the process of closing down.

Topaz

Topaz is one of the oldest gemstones known to man and, before scientists were able to identify gemstones through microscopes and refractometers, most yellowish gemstones were called topaz.

Gem quality topaz was first found in Australia in the 1870s as a by-product of metal-mining activities – usually tin-mining. In fact, topaz, along with aquamarine and quartz gemstones, were tossed aside in the early days. Now, topaz is most often mined in secondary alluvial gravels from rivers or even sandy beaches at low tide.

The topaz found in Australia is light colored material but with heat or irradiation treatment the popular blue and pink colors can be achieved.

Chrysoberyl

Chrysoberyl is a durable gemstone (rated at 8.5 on Mohs hardness scale) which tends to come in yellowish tones. Its most famous variety is the very rare and expensive color-change Alexandrite gemstone.

The bright yellow chrysoberyls from Australia have an unusually high refractive index which gives them a much sought after brilliance not found in this gemstone in other countries.

Despite the name they are not part of the beryl family but make a very attractive gemstone for jewelry at very reasonable prices.

Prehnite

Prehnite was originally discovered in South Africa a couple of hundred years ago and is still the premier source of this fascinating green to yellow gemstone but a golden hued version from the Northern Territory in Australia is gaining fame for its beauty.

Prehnite was the first gemstone to be named after an individual person – Colonel Hendrik von Prehn, who was the governor of the Cape of Good Hope in the late 1700s where this lovely gemstone was first located. The Australian Aborigines believe that prehnite will absorb the warmth and light of the sun during the day and keep away the cold and dangers of the night.

Zircon

Zircon is an historic crystal both in terms of mankind and our planet. A piece of zircon found in Australia in 2014 has been dated back nearly 4.5 billion years making it virtually as old as the earth itself.

Zircon is a very popular gemstone with a reasonable durability which is rated 7.5 on Mohs hardness scale and available in a wide range of colors making it very suitable for all sorts of jewelry items.

Australia has the world largest deposits of zircon but this is mostly for industrial use – it makes great sandpaper. However, the alluvial deposits found in Queensland, New South Wales and Tasmania have been a great source of gemstone quality zircons.

Most blue and clear zircons are heat treated but lots of the richer red, orange and brown colored gemstones are completely natural.

Quartz

Amethyst, citrine and smoky quartz can be found in several places across Australia. The most prolific source is Kingsgate in north east New South Wales where some enormous crystals, especially Smoky Quartz, have been found. However, quartzes such as amethyst have also been discovered in Broken Hill further south and near Stanthorpe up in Queensland.

Jade

There are two minerals that are usually referred to as Jade, nephrite and jadeite, although many other greenish minerals have also been called jade either by mistake or for nefarious reasons.

Humans have been using jade for ornaments and tools for thousands of years, even fashioning weapons out of it since it is such a tough and dense material.

In 1965, a farmer was working in his field in Cowell, South Australia, when he dug up a 4kg boulder which turned out to be a piece of nephrite jade! It was estimated that the Eyre Peninsula where Cowell is located contains 80,000 tonnes of nephrite jade and it has become a premier source for the world.

Chrysoprase

The name 'chrysoprase' originates from the Greek words, 'chrusos' and 'prason', translating into 'gold' and 'leek', respectively; referring to its leek or apple green color and bright hues.

Chrysoprase, like all other varieties of cryptocrystalline quartz, is made up of crystals that are much too fine to be seen as separate particles, even under magnification and is a type of chalcedony.

Its cheerful green color, affordability, hardness and durability make it an ideal gemstone for all manner of jewelry items and it is sometimes sold in Asian markets as Australian Jade. The best examples come from Mt Davies in north-west South Australia and the famous Marlborough deposit in Queensland.

Chrysocolla

The most sought-after, and thus, most expensive, chrysocolla gemstones are the bright blue or green ones with turquoise and teal being the favored colors. The hue is caused by the presence of copper in the mineral make-up of the gemstone when forming.

Pure chrysocolla is both rare and quite soft for a gemstone so it is usually found combined with other minerals. This creates the interesting patterns that decorate the surface of the stone and makes it considerably more durable.

The large sizes and unique markings make chrysocolla ideal for one-off jewelry pieces or artisan hobby making items.

Coral

Coral is an organic gemstone as it has biological origins rather than mineral origins – similar to pearl, amber and jet. Red coral was historically sourced in the Mediterranean and the Red Sea and very much prized by Ancient Greeks and Romans for its beauty and spiritual power.

We are probably all aware that coral reefs around the world are under threat from poor fishing techniques and coral bleaching from rising water temperatures. Australia has some the world's strictest rules when it comes to protective legislation for their natural environment.

Australia produces some of the finest red and pink coral as well as some of extremely rare all natural blue coral.

Variscite

Variscite is a little known but intriguing gemstone which is usually more of interest to collectors or those keen on the spiritual side of gems than someone wanting to create items of jewelry. Saying that, a large piece of variscite could be made into a very unique pendant or brooch with a little imagination.

Variscite was originally found in central Europe and was named after an area in Germany where huge deposits were discovered in the 1800s. Since then Utah in the USA and Queensland in Australia have become important sources of this patterned green gemstone.

Tiger's Eye

Tigers's Eye gemstones are a usually golden brown color with black and orange stripes and bands that give them an almost organic or woody look. They are as much admired for their spiritual prowess as their interesting look.

The Tiger's Eye found in Australia generally comes from the deserts of Western Australia and includes the Marra Mamba variety which can feature red, blue and yellow colors.

Jasper

Jasper is a type of chalcedony gemstone which contains various other minerals that help create its banded, mottled, multi-colored appearance. In fact the word Jasper means spotted or speckled stone.

Australia is home to a special type of Jasper known as Mookaite which has particularly bright colors and interesting decoration.

Pearls

The story of Australia's pearling industry would make quite a movie, in fact it would probably be a hit Netflix series full of untold riches, shark and crocodile attacks, rampant racism, war and adventure plus roles for every film star from Australia, the UK, Japan, China, the Philippines and several other countries besides.

Broome in North Western Australia and the Central Coastal region just above Sydney in New South Wales are the most famous sources of pearls in Australia but nowadays cultured pearls are produced in various locations in the tropical waters of Queensland and the Northern Territory too.

A cultured pearl is not fake or man-made; it is created by an oyster. Instead of relying on chance for pearls, a small nucleus is placed inside farmed oysters to help them produce better quality and more consistent pearls. This method eliminates the need for extensive deep-sea diving and mass oyster collection.

Classic creamy white pearls remain the most popular but silver, gold, pink, gray and even blue and black versions are available.