BOULDER OPAL ROUGH PARCEL
Boulder Opal Rough Parcel. A selection of Opals in green, blue and purple colour. Ready for jewellery making or as specimens. A collection from various jars with great variety of colour and Queensland locations. This lot of rocks are from Boulder Opal gemstone. Photos are with dry and wet stones outside. This is a mixed parcel of Boulder Opal from various locations in Queensland. Some of these pieces have opal on several sides of the matrix rock. These lots are popular as always at a bargain price.
8 Pieces, 494g.
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.