Millions of years have created this beautiful gemstone, directly from the Winton mines in Australia. This stunning rough boulder opal is 100% natural and untreated. It boasts high brilliance and beautiful flashes of multicolors . Very Beautiful Opal Natural Boulder Opal Rough Australian, Winton 39.6 cts - 6.92 grams 1 piece - 21 x 16 x 11 mm about UNTREATED! Lamp light condition! Photo wet piece please be careful with the description and measures Standard shipping ( 2-7 days for Italy ) ( 10-20 days for Europe ) ( 15-40 days for rest of the world )