Geologic: Opal is still considered a mineral for historical reasons, although it is amorphous and therefore referred to as a mineraloid. The “opalescent” effect is caused by numerous tiny silica spheres stacked and bonded with silica and water called hydrated silicon dioxide. Once solid, Opal maintains a water content of 3%-21%.
Chemical composition: SiO2 · nH2O; Hardness: 5.5-6.5
Metaphysical: Opal amplifies one’s own energies and has been used for centuries as a vision stone. The iridescent properties of Opal reflect one’s deepest thoughts and feelings for examination, making this stone a perfect tool for profound inner work.