At first glance, this looks to be just another breathtaking image of a nebula space, but it's actually just an opal. According to the auction house selling the opal, "The piece has a botryoidal jasper formation which forms a unique inclusion. The 'nebula' inside is caused by Jasper, a microcrystalline variety of the mineral Quartz." Continue reading for another picture and more information.
This Opal was mined in Opal Butte, Oregon at a deposit known since the late 1800's. Opal is basically a hydrated amorphous form of silica, with water content ranging from 3%-21%. It's deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being "most commonly found with limonite, sandstone, rhyolite, marl and basalt," says The Daily Mail.