Types Of Opal With Photos - Geology In

Matrix opal, From Queensland Australia

The term matrix opal is commonly used where the opal is intimately diffused as infillings of pores or holes between grains of the host rock in which it was formed. Boulder matrix opal is found in Queensland and can be distinguished by the ironstone host rock.

Andamooka matrix opal is a porous material from Andamooka,South Australia, Which may be enhanced by soaking the specimen in a sugar solution and then boiling in acid to deposit carbon in the available pore spaces, resulting in a dark background.

Common Opal

These don't exhibit play-of-color but come in various colors and forms, including:

Hyalite

Hyalite, from Megyaszó (Hungary). Copyright: Stone Ásványfotós

Hyalite or Mullers Glass, is a colourless opal which gives the appearance of glass. Rarely, it does display a faint tint of colour (blue, green or yellow). It is also sometimes referred to as water opal, too, when it is from Mexico. The two most notable locations of this type of opal are Oregon and Mexico.

Girasol opal is a type of hyalite opal that exhibits a bluish glow or sheen that follows the light source around.

Hydrophane Opal

Hydrophane opal. Photo: James St. John

Hydrophane opals are opals that have a higher porosity and will absorb water, when in contact. You can easily spot a hydrophane opal because when placed in water, they will become transparent and their colors subdued.When dry, hydrophane opal can be opaque or milky-white. But when immersed in water, it becomes transparent or translucent, revealing its true colors and patterns. This characteristic gives it the name "hydrophane," which means "water-loving" in Greek. It is often used in jewelry and other decorative items.

Peruvian opal

Stunning Blue Green Peruvian OpalPhoto : © Trudi Unsworth

Peruvian opal is a type of opal that is found in the Andes Mountains of Peru. It can come in a variety of colors, including pink, blue, green, and yellow. Peruvian opal is often matrix opal, which means that it is opal that is mixed with other minerals such as ironstone or sandstone.

Honey Opal

Bright honey opal from hungary

Honey opal refers to a variety of opal with a yellow, orange, or brown body color. It can be translucent or clear and have a resinous to glassy appearance. It may or may not have play-of-colour. Honey opal is found in various locations around the world, including Australia, Ethiopia, Mexico, and the United States.

Jelly opal - Water opal

Photo: OpalTrove

The jelly opal, also known as the water opal, is a unique opal variety that has a gelatinous appearance. The jelly movement across the jelly opal gemstone body resembles the flow of water, which is likely behind the stone’s alternate name, “water opal.” Jelly opals get their gelatinous appearance from a couple of features: thickness and transparency. It is found in Mexico and Ethiopia.

Pink opal

Pink opal is a type of opal that has a pink color. It can be found in a variety of shades, from light pink to deep rose. Pink opal is often found in Australia, Peru and Ethiopia. It can be transparent, translucent, or opaque. Pink opal is often used in jewelry, but it can be delicate and should be protected from water and harsh chemicals.

Synthetic opal

White Gilson Snythetic Opals

Opals of all varieties have been synthesized experimentally and commercially. The discovery of the ordered sphere structure of precious opal led to its synthesis by Pierre Gilson in 1974. The resulting material is distinguishable from natural opal by its regularity; under magnification, the patches of color are seen to be arranged in a "lizard skin" or "chicken wire" pattern. Furthermore, synthetic opals do not fluoresce under ultraviolet light. Synthetics are also generally lower in density and are often highly porous.

Doublet Opals: Opals that are made by gluing a thin layer of opal to a backing of another material, such as black glass or obsidian. Doublet opals are less expensive than solid opals, but they are not as durable.

Triplet Opals: Opals that are made by gluing a thin layer of opal to a backing of another material, such as black glass or obsidian, and then covering the top with a layer of clear glass or plastic. Triplet opals are less expensive than solid opals, but they are not as durable as doublet opals.