Gem-grade Boulder Opal Specimen
Flag of Australia Mine, Koroit, Queensland, Australia
Discovered in the southern-most opal mining region of Queensland known for the occurrence of precious opal in siliceous ironstone nodulesthese are referred to in the mineral hobby as "nobbies". As the typical size is usually about 5mm across, this is an extrememly large example of its type, weighing approximately 5086 carats (2.2 lbs). The ironstone matrix has been contour polished to reveal the brilliant play-of-color of the opalthe result of silica seeping into fissuresforming an intricate and very gemmy spider's web pattern throughout in electric purple, neon blue and green as well as tangerine orange colors. Measures 5 ½ x 5 x 3 in
Sold for
US$ 13,750
inc. premium
Category:
Natural History
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