For use in jewellery, most opal is cut and polished to form a cabochon, a convex shape that maximises the viewing angles through which an opal's play of colour can be observed. "Natural" opal refers to …
Explore the vibrant world of gemstones! Learn about the different types of opal and where to find them in our comprehensive guide.
Photos of opal from around the world. Guidance for people who want to buy opal, see different types of opal, understand their names, learn about synthetics and imitations.
Opal is the product of seasonal rains that drenched dry ground in regions such as Australia’s semi-desert “Outback.” It is known for its unique display of flashing rainbow colors.
Opal gems are so unique you’ll need a special vocabulary to describe them. Learn all about the many opal varieties and how to evaluate them.
Opal, silica mineral extensively used as a gemstone, a submicrocrystalline variety of cristobalite. In ancient times opal was included among the noble gems and was ranked second only …
Definition: Opals are a type of mineraloid, which means they lack the crystalline structure of typical minerals. Instead, opals are composed of tiny spheres of silica, often arranged in a closely …
Opal gemstones are hydrated silica crystals that form over millions of years. Learn about opal details, including stone meanings and symbolism, history, pricing, and value.