I’ve been wondering for quite some time about this – there are a lot of shops selling opal in Melbourne CBD area. I just found out that opal is the national gem for Australia.

Australia has the largest opal fields in the world, so large that it is bigger than those found in the rest of the world combined. Australian opals are valued for their stability as well as brilliance. Opals from other countries are associated with volcanic rock and have high water content and tend to crack or craze during cutting or polishing, or during hot or dry conditions.

Australia’s precious opals include black opal, white opal, crystal opal, fire opal and boulder opal.

(Source: Opal Auction)

(Source: Swiss Gem Shop)

(Source: Black Opal World)

(Source: GeoGallery)

(Source: Facets)

Opal, also known to Indigenous people as the “fire of the desert”, is a powerful symbol of Australia’s arid interior. The most famous is black opal from Lightning Ridge in New South Wales. It was proclaimed as Australia’s national gemstone on 27 July 1993.

Text source: Australian Government