Glossary

Opal

Opal is a gemstone whose chemical composition is an amorphous, gelatinous, hydrous silica containing varying degrees of water and traces of metal oxides. The opal called fire opal is often carved, engraved or faceted.

There are two varieties of opal : the iridescent precious opal, known also as the noble opal, and the milky white common opal.

See also:
"Opal" is in the UNSPSC Code "54121603"
  Opal gemstones

Ref: 123977/2006-10-18


Other Database Pages Exist for this Phrase:
Chemical (A chemical substance is any material with a ...)
Nopalitos (Nopalitos refers to a small strips from the ...)

Related Articles

Compound ■■■■■■
- In an industrial context, a compound is a substance that is made up of two or more elements that are . . . Read More
Halide ■■■■■
Halide pertains to a chemical compound of a halogen with a more electropositive element or group; - . . . Read More
Mixture ■■■■■
Mixture: ; In chemistry, a mixture is a material system made up of two or more different substances which . . . Read More
Valve ■■■■■
 ; - A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, . . . Read More
Coloring ■■■■■
Coloring agent pertains to colored aggregates; Colored aggregates or mineral oxides ground finer than . . . Read More
Purification ■■■■■
Purification is the process of rendering something pure, ie. clean of foreign elements and/or pollution; . . . Read More
Separation ■■■■■
Separation: ; In the industrial context, "separation" refers to the process of dividing or separating . . . Read More
Zinc oxide ■■■■
Zinc oxide with chemical symbol ZnO, is described as an amorphous white powder used as a pigment in plastics. . . . Read More
X-ray photoelectron spectroscopy ■■■■
X-ray photoelectron spectroscopy (XPS) is a surface sensitive analytic tool used to study the surface . . . Read More
Chemical ■■■■
The term chemical may refer to the following:; - - a substance with a constant chemical composition and . . . Read More