Opals are among the most fascinating stone out there. They are transparent and often milk blue, so you can look at., As it were through the stone Opals have been mined at the time of the Romans, Assyrians and Babylonians. There have been attributed magical powers. Today it is still a mystery what the exact composition of Opal's. Because there is an unknown substance (designated 'n'), where the scholars are still not exactly. Quite special, right?