Green Flash Black Opal 4.15 ct
Natural Solid Untreated Australian Black Opal Polished Stone
Weight: 4.15 carats
Dimensions: 14.6×10.6×4.1 mm
Source: Lightning Ridge, NSW, Australia
Size and weight are approximate
Lightning Ridge is a town located in the central northern area of New South Wales in Australia. The town is very close to the Queensland border. Lightning Ridge is very well known for its black opals; the best and most expensive opals in the world. This is why Lightning Ridge is known as the black opal capital of the world. The name originated from some explorers passing through that found the bodies of a farmer and his large flock of sheep that had been struck by lightning. Electrical storms are very common in the area, and throughout the Australian Outback. The town is also a famous archaeological site for dinosaur bones, some of which are opalised.
Black Opal is the most rarest type of Opal, only found in a very few places in the world (mainly Lightning Ridge in NSW, Australia however some has been found in Mintabie and other small mine sites). Black Opal is non transparent. If you shine light onto it you will not be able to see through the Opal. It is made up of potch and magnificent colours and patterns. Because Black Opal is so rare and also so beautiful, it is the most expensive type of Opal you will find. Black Opal is purchased for investment, as well as for jewellery making or simply just as souvenirs of Australia. Black opal is classified as opals that have a dark body tone of N1-N4.The term Black Opal does not mean that the Opal is dull or dark. Some of the brightest and most beautiful opals are Black Opals. The term simply refers to the body tone of the stone.
Dark Opals are also found in the same region as Black Opals; in Lightning Ridge. It has a dark body tone but not dark enough to be classified as a Black Opal. Dark Opals have a body tone of N3 to N7. Despite the body tone overlapping with Black Opals (N3 and N4), the differentiation may be in the colours and patterns evident. A lighter body tone based black opal of N3 and N4 will have bright, evident colors and patterns showing which differenciates it from a semi black opal of the same body tone (N3 or N4).
Black Crystal Opals are black or semi black body tone based opals that are transparent (they let light thru). Typically the body tone measurement of a crystal opal is N8 or N9, however black opals and semi black opals range from N1 to N7. This makes classifying a black crystal difficult. We often don’t grade the body tone of black crystals as it may become confusing to the person interpreting information. Some opal sellers may classify them on the lower end of the body tone guide whilst others may classify them on the higher end.
Lightning Ridge are the most valuable types of opals. There have been some discovered that go into the millions of dollars. Unique and rare patterns, rare colors (such as red and rainbow), and brightness of the opals determine the value. Black Opals have been used in high end jewelry by jewelers around the world for centuries. They are a very high demand and highly valuable gemstone. Black Opals set in jewelry were a favourite by Queen Victoria who ruled the Commonwealth of the World in the 1800’s. Black Opals have also been a common investment by people who wish to invest in tangible assets that are easily movable. Rare pattern and colored Lightning Ridge Opals appreciate over time, as they are becoming scarce and harder to obtain by miners as the area becomes desolate by mining.