BOULDER OPAL POLISHED GEM

BOULDER OPAL POLISHED GEM

A Boulder Opal Polished Gem Stone.  A great splash of blurple coloured Opal to show off to your friends (that’s between blue and purple).  This beauty has been cut by a local opal cutter and shows 3 dimensional form and contours.  This Opal would suit jewellery in pendant or ring form.  Comes in a good round acrylic display pod.

Location:
Queensland, Australia.

Dimensions:
1.15cm x 2.53cm x 0.52cm, 1.8g, 9.1ct.

Opal: SiO₂ · nH₂O Hydrated Silicon Dioxide.
Boulder Opal is a variety of Precious Opal found in Queensland, Australia, 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 probably is derived from the Sanskrit name for precious stone- upala.  Opal is 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.