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

Green Jelly Opal (rare color and locality)

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

Opal, Properties, Types & Uses

Opal: Mineral information, data and localities.

What Is Opal - Gemstone Facts and Information

Polished Highly Selected Rare Dark Green Opal Palm Stones / Gallets - sold per kg - From Antsirabe, Madagascar

Opal-AG: Mineral information, data and localities.

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

Opal Geoscience Australia

Opal / (variety - “Opal-AN”) / (variety - “Hyalite Opal”) / (“Blood Vessel Opal”) / Locality - San Luis Potosi, Mexico

Opal: The mineral Opal (black, white, fire) information and pictures

Boulder opal