Fire Opal
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.
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
