Black opals are the rarest of opals - consisting of only 5% of opals in existence. The largest known deposits of black opals is found in Lightning Ridge, New South Wales, Australia.
The town of Lightning Ridge has only about a thousand year-round inhabitants, but it is a thriving tourist spot, with several camper-trailer (aka caravan) and camping parks, a a bowling club, and an Olympic-size swimming pool.
Tourists come there to fossick, or noodle, which are Australian terms for prospecting. The Visitor Information Center in the town lets visitors know which areas are open to such activities. In addition, visitors can go to The Australian Opal Centre, 3/11 Morilla St. to see displays of opal and fossils. And they can visit the Walk In Mine to take an underground tour of the opal mines.
The town is accessible by road from Sydney (720km), Brisbane (750km) and Melbourne (1,200km) and is also serviced by CountryLink.
There are 4 main opal types:
- Black
- Boulder
- Crystal
- White
Black opal shows play-of-color against a black background, Boulder against a brown background, Crystal against a transparent background and White has play-of-colour against white.
The internal structure of an opal is unique. When light shines across it at certain angles, a phenomenon is created called play-of-color”. The complete spectrum should be visible: red, orange, yellow, green, blue and violet. If the opal flashes only one color, red tends to be the most valuable. Indeed, opals that flash mainly greens and blues are less valuable than those that show red, yellow and orange.
See the black opals at auction on opalauctions.com