Buying opal is a very difficult yet rewarding experience. Opal is a very confusing gem, this is due to a variety of reasons, these include:

worldwide shortage of precious opal
large range of varietys and types
no standard for nomenclature or classification
lack of general knowledge about specific opal
many market points, miner, cutter/polisher, jeweler, marketers

Good places to buy opal are hard to find!

Determine whether you are looking at a doublet, a triplet, or a solid opal. Doublets & triplets consist of a very thin slice of opal, cemented onto a black backing. This causes the stone to be dark & bright in colour. The advantage of buying a doublet or triplet is lower price as they are much cheaper to produce - however the disadvantage is they may eventually be destroyed if repeatedly immersed in water. Solid opals are therefore considered a quality, long-term investment.

Black opals, boulder opals, & white opals - These are all different types of opals, the difference being that they are found in different parts of Australia, and each have individual appearances. Black opals are the 'Rolls Royce' of opals, and often have a certain price attachment associated with their status and rarity. Boulder opals are the much lesser known cousin, with equally stunning colour, however the opal forms in thin veins on an ironstone backing (hence the dark colour), therefore the price is generally much less per carat due to the ironstone content of the stone. Be wary of people selling boulder opal at a price 'per carat', leaving a heavy ironstone back on the stone. This is a sneaky way of boosting the price of the stone. Boulder opals are the most 'hardy' of all opals due to their very hard ironstone backing.

White opals have a 'milky' white body tone, and are much more common. The white body tone often causes the colour to be less bright, however by the same token I must say that some of the most beautiful opal I have ever seen has been white. Oh, and let's not forget crystal opals - this is any type of opal with a translucent / transparent quality, and can add value to a stone when combined with good colour.

Pick a stone that appeals to you! Each stone has an individual personality, much like people, so nobody can tell you what your opal should look like. Red on black is most valuable, but if you like blue, go for a blue stone!

Consider what you are going to be using the stone for. Shape and size is an important factor when considering the setting for jewellery. If you are buying a high quality stone, consider matching it with a high quality setting.

Brightness, brightness, brightness. A brilliant stone is valuable, no matter the colour or body tone.
Colour - red is the most valuable, followed by orange, yellow, green, and then blue being the most common.

Certificates of Authenticity - always ask for a signed certificate of authenticity. Not only is it good for insurance and purposes, and re-sale value, you are also making the dealer accountable.
The value of a stone - read our article on how opal is valued. Educate yourself on the general principles of how opals are valued and compare stones. There is no 'formula' for figuring out the value of a stone, although people have tried to formalise this process. There is no substitute for years of experience mining, cutting, and valuing stones. Buy from someone who has a good reputation, preferably someone who cuts or mines the stones themselves.

Cracks and faults - if you are inspecting the stone in person, allow it to dry, then hold it up against a lamp to inspect it for cracks. Be careful not to mistake natural formation lines in opal for cracks (eventually you will be able to tell the difference). A cracked stone is virtually worthless. The person you are buying the stone from has an obligation to make you aware of any cracks or faults in the stone before you purchase it.

GST (tax) - if you are buying from an Australian company, remember that your purchase is not subject to our 10% goods & services tax. Make sure they are passing on the saving to you!