Opal is hydrated amorphous form of silica. This kind of gems contain a high amount of water in them. The water may range from 3% to 21% of the weight. The most common water content goes from 6% to 10%. Opals are gems that are classified as non-crystals. They can also be found with limonite, sandstone, rhyolite, marl and basalt. Opals are most common in Australia. Australia contains 80% of all opals in the world. It is their national gem.
If you look closer in to this kind of gem you will become startled. The view inside the gems breathtaking. Its like you are looking on some other planet far away. The forms that are created inside are unique and there is no way to find 2 opals with the same pattern. There are many types of opals. Fire, ocean, blue, black with many kind of different colors in it and much more different types.
Fire Opal
Ocean Opal
Photos taken from this source
Galaxy opal
Image by Chelsea Gomez via Flickr
Blue Opal
Yowah Nut Opal, Australia
Fire Opal
Image by greenzowie via Flickr
Black Solid Opal
Image by Peter & Barbara via Flickr
Opal from Queensland, Australia
