One of the many members of the quartz family, opal is hardened silica gel, usually containing 5-10% water in submicroscopic pores. Opal’s structure varies from essentially amorphous to partially crystalline. Precious opal is the least crystalline form, consisting of a regular arrangement of tiny transparent silica spheres with water in the intervening spaces. Opal’s name comes from Sanskrit upala, meaning “precious stone.” Metaphysically opal is used for love and light. Fine specimens of opal are found in Australia, Oregon, Peru, Mexico, and Ethiopia.