Learn about Australian Opal

What is Opal?

Opal is a hardened gel of silica and water (usually 6 – 10%). Its physical properties vary with differences in its structure and water content. Unlike other minerals opal is amorphous, with no definite crystal structure. Opal is a common mineral, found in many countries and various geological environments. To distinguish this ordinary opal from the precious opal used in jewelry, we call it common opal (sometimes called "potch").