Color patterns In Opal

The vast majority of precious opal may show unique pattern to the play-of-color. The major patterns tend to fall into one of the following categories:

Pinfire: This is a mass of pinpoints, flashing different colors as the stone is moved. All colors may be seen, but red is most desirable. This pattern is fairly common and is the least sought after.

Harlequin or mosaic: Harlequin is the rarest and one of the most beautiful arrangements of play-of-color in opal; resembling a harlequin clown's costume. The true harlequin pattern appears as squares of equal size and regular arrangement. The pure pattern is particularly valuable. The color display consists of units of uneven size with distorted angles. Some dealers use the term only for the rare pattern described above, whereas others will allow more irregularity.

Flash: Flash refers to opals in which the play-of-color appears in sudden flashes that disappear or change as the stone is moved. The colors may be any shade from blue (most common) through the progressively rarer green, yellow, orange and red, with an occasional flash of violet or purple.

Red flash is most prized, but opals with violet or purple are also highly desirable due to their rarity. However, just the presence of a particular color does not make for a valuable stone; the full range of colors should be present. Stones which display all the colors, and which have colors that change with the angle of view are the most valuable opals of the type.

Exploding flash: The pattern moves outwards in all directions as the stone is moved, with red usually changing to orange or green.

Rolling flash: The patch of color moves as the stone is turned.

Broad flash: This pattern is made up of color flashes larger than 2 mm in size which are visible only at certain angles. If the flash covers a wide area it is called 'sheen'. Many precious opals fall into this category.

Other patterns include:

Floral: Resembles floral patterns seen on printed dress fabrics. The units of color are large than pinfire, more or less rounded, but slightly irregular.

Peacock's tail: Green and blue radiating out like a peacock displaying its tail feathers.

Palette: Resembles an artist's palette with patches of paint.