BOULDER OPAL ROUGH PARCEL
Boulder Opal Rough Parcel. A great parcel of beautiful rough Boulder Opal. It is getting hard to find good rough opal nowadays. Most is sold already worked. I love opal in the rough and these pieces also have the attractive markings in the base rock. A beaut find to work or keep as is. One photo was taken of the stones wet. Buy it while it’s available. Gotta love Aussie Boulder Opal!
7 Pieces, 193g.
nH2O Hydrated Silicon Dioxide.
Boulder Opal Precious Opal found in Queensland, Australia. Found as cracks or coatings in and around ironstone/sandstone boulders. Opal has been a popular gem for many centuries and has a very interesting structure. The name Opal, derived from the Sanskrit name for precious stone upala.
Opal, considered a mineraloid because this structure is not truly crystalline. The chemistry of Opal is primarily SiO2 and varying amounts of water. The amount of water varies from 5 -10% and greater. This water can help geologists determine the temperature of the host rock at the time the opal formed.