Opal: Mineral information, data and localities.

Although it is still (2007) regarded as a mineral species for historical reasons, opal is not a true mineral in the accepted sense of the word as it is

Opal Geoscience Australia

Opal-AN (Hyalite Opal) with Carbonate-rich Fluorapatite (var: Staffelite) / Locality - Valec (Waltsch), Bohemia, Czech Republic

Polished Dendritic White Opal Hearts x 8 From Moralambo, Madagascar

Boulder opal

Opal : Properties, Formation, Uses and Deposits » Geology Science

Precious Opal: Mineral information, data and localities.

Opal, Properties, Types & Uses

Opal-An (hyalite opal) from Zacatecas, Mexico. (A) Natural light. (B)

Rare $675,000 opal makes public debut

Opal-AG: Mineral information, data and localities.