Many of you might be aware that Opal Horizon, a Brisbane-based Opal mining & wholesaling company have launched a campaign to bring in a “globally quantifiable” grading system for Australia’s national gem stone the Opal. The idea is to bring a standard grading system across the Opal industry so that Opal dealers can capitalise to the full potential on their worth. The new grading system being proposed by Opal Horizon is based on judging three aspects of each Opal: Category – the presence & degree of host rock Colour – Opal face, body tome, play of colour, brightness, pattern, dire...