Highly figurative 44.25ct Koroit boulder Opal

This exotic boulder opal is very well marbled with a swirling matrix that frames glittering pops of pure black opal crystal veins. It has a glossy luster, and measures 29mm x 22mm x 8mm. This is an untreated boulder opal, it contains pure opal and matrix. This gem was sourced from the Koroit opal fields in the Paroo shire of southwest Australia.