Colours & Patterns in Australian Opal
An Opal's beauty is unique and made from the amazing play of spectral colours unique to this gemstone. This originates from the breaking up of white light due to the three dimensional spherical shaped micro-structure of the silica particles inherent in the opal (these can only be detected with an electron microscope).
Similar phenomena of colour hues can be observed when oil lies on water or the play of light giving rise to a rainbow.
Generally, the value of an opal is determined by the type of opal, the predominant colours it exhibits, the clarity or brilliance of these colours and the patterns in which the colours are arrayed. Good patterns of diffracted colours have an enormous impact on the value of the opal. Pinfire and small type patterns are more common, thus less expensive than broad patterns or large flashes. Distinct patterns such as Rolling flash, Straw pattern, Chinese Writing, Ribbon, and especially true Harlequin patterns, are very rare and considered collectors' items.
Opalbeds all Rights Reserved
Similar phenomena of colour hues can be observed when oil lies on water or the play of light giving rise to a rainbow.
Generally, the value of an opal is determined by the type of opal, the predominant colours it exhibits, the clarity or brilliance of these colours and the patterns in which the colours are arrayed. Good patterns of diffracted colours have an enormous impact on the value of the opal. Pinfire and small type patterns are more common, thus less expensive than broad patterns or large flashes. Distinct patterns such as Rolling flash, Straw pattern, Chinese Writing, Ribbon, and especially true Harlequin patterns, are very rare and considered collectors' items.
Opalbeds all Rights Reserved