This huge Black Opal specimen weights a stunning 391 carats and has a beautyfull blue/dark blue/royal blue/green-turquise-purple colorplay. Only the opal bar is polished!! Everything else is in absolute natural rough condition (Natural sandstone/clay) . there are due to its huge dimensions and mining some natural cracks (sold as specimen) but there is a chance of recutting this piece to get large gem colored blue gemstones (but i would leave as a specimen).. The blues are darker and a bit more blue/green (impossible to show perfectly)!! Perfect collectors piece.