Eildon Hill

Today we got up late, but decided to go and investigate the Opal museum and shop. We got the train from Sandgate and headed to the Albion stop. A 10 minute (?) walk uphill got us to the Museum. As we went in we were met by the owner, Geoff McDonald who gave us a personal tour around his small but informative museum.
He is an opal enthusiast and is part owner of an Opal mine - "Now, you’ve probably heard of gold fever, well, opal fever is just as real. And I’m proud to say that I HAVE IT. It gets into your blood and people in the industry love the game. A chance to discover the treasure underneath the sun-burnt land - a dream that is only one pick axe swing away. And if opal is found. The wheeling-and-dealing begins in the GAME OF STONES!
At the Brisbane opal museum you can feel the love for this special stone. The Opal is something truly special, where unlike most things these days, when you see it and hold it in your hands you can actually see the value!"
The Museum is divided into sections, in the first area we learnt about where most opals come from in Australia and how they are made from Geoff and a video, we were also shown the way the stone is cut and the machine that is used to polish the stones. The next section explained more about the life of the miner and the various ways the stone is mined. We were then shown a number of different types of opal in their rough and cut state. The rest of the exhibits we were able to discover in our own time - opalised shells, opalised wood, gems and rough stone.
Opal is formed from a solution of silicon dioxide and water. As water runs down through the earth, it picks up silica from sandstone, and carries this silica-rich solution into cracks and voids , caused by natural faults or decomposing fossils. As the water evaporates, it leaves behind a silica deposit. This cycle repeats over very long periods of time, and eventually opal is formed.
TYPES OF OPAL
Black opal is characterised by a dark body tone causing brightness of colour which is unmatched by lighter opals. The term 'black opal' does not mean that the stone is completely black (a common mistake), it simply means the stone has a dark body tone in comparison to a white opal.
Also known as 'milky opal', white opal features light white body tones, and is mined in South Australia. White opal is more common and because of its body tone, generally does not show the colour as well as black opal.
Boulder opal forms on ironstone boulders in Queensland. This type of opal is often cut with the ironstone left on the back, as the opal seam is usually quite thin. Boulder Opal has a tendency to cleave; when cleaved the "split" leaves two faces of opal, with a naturally polished face.
Crystal opal is any of the above kind of opal which has a transparent or semi-transparent body tone - i.e. you can see through the stone. Crystal opal can have a dark or light body tone, leading to the terms "black crystal opal" and "white crystal opal".
Fire Opal is the term has been used to describe any Australian kinds of opal (normally a black opal shows it best) which displays a significant amount of red colouring. Red of course is the rarest colour, so these are quite valuable.
Matrix opal is where the opal occurs as a network of veins or infilling of voids or between grains of the host rock (sandstone or ironstone). It generally shows fine pinfire colour in the natural state.
After learning about the opal on the tour, the jewellery shop awaits. There were some beautiful pieces and if I am unable to find a Queensland Sapphire ring to replace my engagement ring (which I cannot wear due to a broken setting) an Opal one may be the next option. We spent a good hour here without realising it. We headed back for lunch in Sandgate with Sarah who had been exploring Brisbane. We spent most of the time left in the afternoon packing for our trip to Bulli.Read more