What Is Opal?
Australian Opal vs Opal from Other Countries
Opal is one of the world’s most fascinating gemstones, prized for its vibrant flashes of colour known as play-of-colour. Unlike diamonds or sapphires, opal is an organic gemstone formed from silica and water over millions of years. When light enters the stone, it diffracts through microscopic silica spheres, creating dazzling colours ranging from fiery reds and oranges to electric blues and greens.
Among all opals found worldwide, Australian opal is considered the finest and most valuable, setting the global benchmark for quality, durability, and brilliance.
What Is Opal Made Of?
Opal is a hydrated form of silica (SiO₂·nH₂O), containing between 3% and 21% water. Its unique internal structure is what creates the legendary colour display. The more uniform and tightly packed the silica spheres are, the more vivid and valuable the opal becomes.
There are two main types:
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Precious opal – displays play-of-colour
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Common opal (potch) – no colour play
Australian mines produce a wide variety of precious opals, many of which are unmatched anywhere else in the world.
Why Australian Opal Is the World’s Best
Australia produces around 95% of the world’s precious opal, making it the undisputed leader in opal quality and supply. It is also Australia’s national gemstone.