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 blue ocean. Very Beautiful Opal Preformed Natural Boulder Opal Rough Australian, Winton 3.7 cts - 0.74 grams 1 piece - 14 x 8 x 4 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 )