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

fire

Ocean Opal

ocean

Photos taken from this source

Galaxy opal

gem

Image by Chelsea Gomez via Flickr

Blue Opal

blue

Image by cobalt123 via Flickr

Yowah Nut Opal, Australia

Yowah Nut, Australia

Image by cobalt123 via Flickr

Fire Opal

fire2

Image by greenzowie via Flickr

Black Solid Opal

Black Solid

Image by Peter & Barbara via Flickr

Opal from Queensland, Australia

From Queensland, Australia

Image by Taifighta via Flickr