There are small spots of natural pitting to the rear edge of the opal. This solid black matrix boulder opal has been mined from the Queensland boulder opal fields.The ironstone of the opal is brown, similar to our natural matrix opals. These opals have been treated to darken the ironstone and then stabilized to fill any small rough edges at the rear of the opal. The opals are then cut and polished normally like all our other opals. We do not use any sealers, coatings or toxic chemicals in the process. The natural gem colors are not altered and are richer only due to the darker contrast of the ironstone. There are smal spots of natural pitting to the rear edge of the opal. We pride ourselves in offering you boulder opal with bright gem colours. We go the extra mile to offer top quality opals in all price ranges. This item is in the category "Jewelry & Watches\Loose Diamonds & Gemstones\Loose Gemstones". The seller is "opals-downunder" and is located in this country: AU. This item can be shipped to North, South, or Latin America, all countries in Europe, China, Japan, Australia.