Opalised fossils are found on most of the opal fields of Australia but one of the most intriguing and interesting of all fossils are the opalised shells commonly found at Coober Pedy, South Australia.

Genuine opalised shells are highly prized amongst collectors but they can be very expensive, especially if they are full colour shells. Some opalised shells have sold for hundreds of dollars per carat. Whilst Visitng Coober Pedy in 2003, I saw one of the most amazing shells found on the field. Needless to say, it was not for sale.

Even potch shells can cost around $20.00 to $25.00 each.

For the past 10 years, we have been making simulated opalised shells (Patent Approved) and these have been extremely popular with tourists visiting Coober Pedy the major world producer of precious opal. The locals call Coober Pedy 'The Opal Capital of the World'.

The simulated opalised shells are made in a tough matrix resembling the sandstone in which the genuine shells are found and the matrix even contains pieces of genuine opal mixed with genuine opal dirt from the opal fields.

We make a number of shell species and can make special orders or blocks with a number of shells specificaly for shop display. These smulated opal shells have a very high visual impact and look like genuine precious opal with it's characteristic play of spectral colours.

Each shell is slightly different and they are made in a variety of sizes ranging from 20 mm to 50 mm.

Prices range from $40.00 each.

Each sample comes complete with description card with a picture of genuine shells and a detailed description of the opalised shells and thier formation.

They are a great educational product as well as an eye catching talking piece. They even fool the opal dealers, who are happy to sell them as a souvenir of Coober Pedy.

We can make them for any opal field, just send some opal dirt and potch from your field and we will do the rest and make them as realistic as possible.

A magnet is attached to the back of each sample so that you can attach them to your fridge, filing cabinet or safe. They make a spectacular high visual impact display and are great conversational pieces.

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We make a number of shell species and can make special orders or blocks with several shells specificaly for shop or museum display.

These simulated opal shells have a very high visual impact and look like genuine precious opal with it's characteristic play of spectral colours. They make great souvenirs and talking pieces. They have been selling at Coober Pedy, South Australia since 1996.

Each shell is slightly different and they are made in a variety of sizes ranging from 20 mm to 50 mm set into matrix containing genuine opal.

Each example is accompanied by a fact card detailing information on formation of opalised shells.

They look spectacular in any setting and make fantastic fridge magnets.

Prices range from $US30.00 each retail. More information
We can make them to your specifications.

Captain-BlueJacks Museum Quality Fossils Replicas, Science Kits, And Native American Jewelry

About 110 million years ago there was a shallow sea which covered much of inland Australia. It is in this sea that many extinct creatures were spawned. We know they existed here from the fossil record of the area.

The varieties of fossils found in these ancient beds, include molluscs such as cockles, mussels, clams and sea snails, belemnites, which were squid like animals that looked similar to cuttlefish, crinoids or sea lilies and some now extinct species of marine reptiles - Ichthyosaurs, Pliosaurs and Plesiosaurs.

Probably the most fascinating, and widely known, of all the opalised fossils are the opalised shells found on the opal fields of Australia, particularly at Coober Pedy.

Opalised shell fossils are unique to the Australian opal fields and top quality shells command high prices.

During this period of the early Cretaceous era cockles were the most common of the molluscs present but other varieties of shell, such as mussels, were also abundant in the Eromanga Sea, as it is known.

How Are Opalised Shells Formed?

The Eromanga Sea was also home to many now extinct marine creatures and may have been the breeding ground for marine reptiles. This is thought because of the number of juvenile fossils found.

When marine animals die, their remains sink to the bottom of the seabed.

The fleshy parts may be eaten by other creatures but the bony or hard calcium remains may become buried under sand or silt and are preserved. With the build up of sediments over millions of years those remaining bony or shell parts may become fossilised.

In some cases the shells, being calcium carbonate, may be dissolved by acids in the soil, leaving cavities which may, in turn, be filled with other minerals, even opal. Sometimes, the cavities are filled with precious opal and these are highly prized amongst collectors.

About 65 Million years ago, the various species of sea reptiles perished along with the dinosaurs, but many of the molluscs survived and their ancestors are still surviving to this day.

It is not known why some species died out completely but the survival of those that remain today could, possibly, be likened to the process whereby an embryo is frozen and later thawed to propagate the species which later evolved into the varieties we see along our shorelines to this day..

The opalised fossils are found by miners, known as gougers, who work the opal fields for precious opal. Opal can be more valuable than diamond and it is the promise of a 'Lucky Strike' that tempts miners away from city life to the harsh and unforgiving conditions encountered in the hot arid regions of Australia's outback.

Shells which contain precious opal fetch very high prices. Dealers value the quality of the opal and then the price is adjusted to take into account the fact that it is an opalised fossil.

Most of the opalised shells are white opal and can be valued up to $1,000 each but crystal opal shells are far more valuable and can be several hundred dollars per carat.

An opalised shell which doesn't have any play of spectral colour is known a 'potch' shell.

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Artificial gems have, for centuries, been popular in costume and fashion jewelry. However, high quality precious opal has never, until now, been truly copied. Our interest in holography started in 1972, but it was not until 1976 when we started using diffraction gratings.

In 1990, we developed a unique method of generating completely random holograms and as a result invented the process to simulate precious opal.

We have a patent on Opalus™, a method of making simulated gemstones and simulated opals for use in costume and fashion jewelry. Although the gems were originally designed for the mass costume jewelry market, the trends have moved towards the gems being set in gold or silver.

Opalus™ (simulated opal - below) is a patented product. The outer shell is composed of high impact acrylic containing over 100 layers of compressed material . Opalus is durable and will not crack or craze. However, it is affected by heat and may be pierced by a hot needle.

We manufacture the gem in a wide variety of shapes and sizes, some of which are quite unique, resembling large high quality opals. Like genuine opal, every stone is different and shows the characteristic play of spectral colours of high quality opals.

These artificial gems are made in two different qualities,

a) the better quality simulated gemstone for durability and;

b) the lower quality simulated gemstones for cost effectiveness.

Our simulated gemstones can be made to order from your own material and can be reproduced to be mirror matched in large or small volumes.

There may be a very slight, and maybe insignificant, colour variation from the original piece but the colour will be constant in batches.

The b) quality simulated gemstones are made in the following standard sizes:

10 mm X 8 mm
14 mm X 10 mm
18 mm X 13 mm

and a variety of round sizes from 8mm to 24mm.

The a) quality gemstones are currently being made in 18 mm X 13 mm and a variety of round sizes as well as some navettes and and baroques for individual setting.

The surface of the a) quality simulated gemstones is made in high impact acrylic for improved durability and may be set in gold or silver jewellery.

These gems are ideal for the wire wrap jewelry enthusiasts as they are not brittle or prone to crazing and cracking.