Oval-shaped cantera opal loose gemstone, approximately 6.5 carats. The term "cantera" in cantera opal comes from the Spanish word meaning "quarry." The rock in which opal is formed is called the host rock, and this host rock is a type of volcanic rock called rhyolite. In Mexico, this rock is called cantera, and because the opal is extracted and polished with the host rock, it is called cantera opal. Most cantera opals are finished in a cabochon cut. The form is like an egg. The main attraction of cantera opal is that the host rock looks like an eggshell, and the opal looks like the contents of an egg, giving it a mysterious and unique charm. The opal part of the cantera opal exhibits an iridescent effect that shimmers with seven colors, making it look like a rainbow is contained within the egg. It would be wonderful to have it made into jewelry, but cantera opal is so irresistibly cute even as a loose gemstone, and it's recommended to keep gazing at it. Each opal is a unique stone. I have kept it as a collection, but I am now putting it up for sale. How about using it as a material for handmade jewelry or for your collection? There are some minor scratches, but they are not noticeable, and it is generally very clean. Please understand that this is a used item before purchasing. The condition may vary depending on the viewer's perspective, so please take a good look at the images and make your judgment. 【Size】 Size: Approximately 10.5mm x 17.5mm x 6mm Weight: Approximately 1.3 grams 【Accessories】 Storage case Thank you for reading to the end. #CommonOpal #Opal #LooseGemstone #NakedStone #Material #CanteraOpal T03669 (Colorful) Color...Brown