Types of Australian Opals

The most famous, diverse and beautiful - Australian opals hold a special place in the gemstone world.

Australia is the largest producer of opals in the world. No other country offers as many varieties of this gemstone.

I frequently get asked how to identify different types of Australian opal. Here is a short guide to the most common varieties:

Black opal - the rarest and most desired opal is found mostly in the Lightning Ridge opal fields of New South Wales. It has a very dark to black body tone, which is created by a precious opal layer forming on a dark common opal, called potch. Black opal can display a wide variety of play of color. The combination of red on black is the rarest.

Blue and green black opals from Lightning Ridge, Australia

Dark opal - more common than black opal, dark opal will have different tones of gray in the body under the play of color. The structure of dark opal is like that of black: layers of play of color over dark toned potch. Dark opal is produced primarily in the Lightning Ridge and Coober Pedy fields but is also found in other mining areas. 

Colorful dark opals from Lightning Ridge, Australia

White opal - the most common and recognized variety of Australian opal with a light/white body tone, resembling frosted glass. The play of color will frequently show the entire rainbow, with the most common colors being green and blue. Most white opal comes from the Coober Pedy fields in South Australia.

White opal in the sunlight from Coober Pedy, Australia

Crystal opal - the transparent variety of precious opal. Crystal opal can be identified by looking to see if light passes through the stone. Crystal opal can also have different tones of body color - from very dark to completely translucent and clear. The play of color usually displays throughout the whole gemstone and will give the impression of having extra depth. Crystal opal is found in all the main mining areas.

A crystal opal from Andamooka, Australia.

 

Boulder opal - this type of Australian opal is found in different regions of Queensland. It has a wide array of precious opal on an Ironstone host. Boulder opal can appear as a layer on Ironstone or in amazing web patterns. 

Boulder opal rough from Queensland, Australia

Liga K., March 30th, 2021