Fortunately, many contemporary Australian jewellery designers are embracing this unique and fiery gemstone with open arms, creating beautiful custom-made pieces that reflect opal’s magical quality and the personality of the owner. High-end European designers such as Dior also pay homage to opal, fascinated by its unique explosions of colour.
While overseas buyers are in constant pursuit of good quality Australian opal, local jewellers are spoilt for choice, including boulder opal from Quilpie, matrix opal from Koroit, crystal opal from White Cliffs, and the prized black opal from Lightning Ridge.
Admittedly, the opal industry has been affected by past tales of “bad luck”, perpetuated by folklore, superstitions, disgruntled diamond traders, and even novelists. However, for every negative story, there is a positive one: In Australian Aboriginal legend, opal was termed the “Rainbow Serpent”, and was admired for its unique energy and beauty.
Jewellers who successfully sell opals tend to stock many different types, from inexpensive triplets through to high quality black opal.
Product knowledge is vital to selling this merchandise; hence staff should be familiar with the various opal types, varieties and their accompanying stories.
A comprehensive opal classification system was developed by the Australian Jewellery and Gemstone Industry Council in collaboration with the Australian Opal and Gemstone Industry Association, the Gemmological Association of Australia, the Lightning Ridge Miners Association and the Jewellers Association of Australia.
Using this system, opal is divided into two forms: precious opal, and common opal or ”potch”. Only the former displays play-of-colour (hue, brightness, pattern, directionality), produced by the diffraction of white light through a micro-structure of orderly arrayed spheres of silica to produce changing spectral hues. Red is the most valuable play-of-colour; however any combination of red, blue and green is also highly desirable, especially in a recognised pattern like flagstone or harlequin.
Natural precious opal can be subdivided into three types: solid opal, boulder opal and matrix opal. These types can be further characterised by body tone and transparency. Body tone, measured on a graduating scale from black (N1-N4), to dark (N5-N6), to white (N7-N9) is the relative darkness or lightness of the opal when viewed face up and is separate to its play-of-colour. Semi-transparent to transparent material known as crystal opal may have a black, dark or light body tone.
Although beauty is in the eye of the beholder, assessing the dollar value of a natural precious opal is a complicated task dependent upon several factors including opal type, body tone, transparency, shape, size, weight, play-of-colour, and cut.
There are several myths regarding how to care for natural precious opal. Some believe it is harmed by contact with oils while others are convinced that opal should be occasionally soaked in water to revive its colour.
Although these anecdotes are fiction, the wearers should take care to avoid abrasion and hard knocks on their opal jewellery.
Megan Austin FGAA FGA Dip DT BA, is an in-house gemmologist and registered valuer for a retail jeweller. For more information about coloured gemstone reports, visit gem.org.au