These stunning earrings are handcrafted from high-quality Sterling Silver and feature a pair of Natural Boulder Opals sourced from Australia, with a 925 stamp of authenticity. As a Natural Opal Type 2, Boulder Opal occurs naturally attached to a host rock with a unique chemical composition. Genuine Natural Australian Boulder Opals are composed of hydrated amorphous concretions of SiO2nH2O silica, formed from closely packed silicon dioxide molecules that fill the crevices of Boulder Opal ironstone. These opals are extremely rare and are exclusively found in select regions of Queensland, Australia. As a result, their value has been known to appreciate up to 15% annually. These earrings are also guaranteed to be free of artificial coloring or dyes, making them the perfect natural and beautiful addition to your jewelry collection. All Australian Opal Cutters Jewellery and Loose Opal items are covered by our international warranty. Please send us an note when you check out if you would like to add any modifications or changes or have a specific colour requirement for your Opal. On request and at an additional charge we are able to change or upgrade your Opal (or change the design) of any item that we offer. The item shown online may not exactly reflect the item you receive as Opals have a living play of colour that can be difficult to capture on camera.