Opal Buying Guide – Seven steps in choosing an opal
Opal Type –
Solid Opal –
Made of a single solid piece of opal, this is the most valuable type of opal. Depending on the rarity of colours and patters Solid Opals can cost as much as a top grade diamond on a per Carat basis.
Boulder Opals –
Thin veins of opal form within the cracks of Ironstone, when these veins are exposed they remain attached to their ironstone backing. Stunning boulder opals are mostly irregular shapes and make fantastic pendants. Boulder Opal is not as expensive as solid opal, but is more expensive than the man made doublet and triplet opals.
Doublet Opal –
A thin slice of opal is backed with a dark piece of stone or plastic – When the stone is set so that the back and sides aren’t visible, it can be very difficult to distinguish a Doublet Opal from a solid opal.
Triplet Opals –
A paper thin slice of opal is mounted onto a black background stone or plastic, and a dome of crystal, glass or plastic is mounted on the front of the opal to both protect the stone, and magnify the colours. Triplet opals are generally cheaper than doublet opals because they contain less actual opal stone.
Opal Body Tone -
Darker Opals are generally rarer and display more vibrant colours, therefore as a general rule, the darker the opal the more valuable it is. Opals come in shades of darkness from Black opal through Dark Opal and White Opal.
Crystal Opals are translucent and may have plays of colour from faint to vibrant. Depending on the intensity of colour crystal opals can range in value.
Play of Colour –
The play of colour in an opal affects the opals value. Naturally Red is the rarest colour found within an opal, the value of colour then decreases through orange opal, yellow opal, green opal and finally blue opal.
Some combinations of colour also occur less often, such as a play of Red and Blue together.
The Play of Colour within an opal takes on certain patterns. This patterning is 100% unique to each opal. Some patterns are rarer than others, and some are more striking than others. The more valuable patterns include Harlequin Opal, Flagstone Opal, Ribbon Opal, Straw Opal, Chinese Writing Opal and Picture Stones Opal. Some other beautiful patterns include Floral Opal, Rolling Flash Opal, Broad Flash Opal and Pinfire Opal.
With solid opals, the Carat weight of the opal plays a big part in its valuation. Oval and round opals can be selected based on measurements in mm.
Opals come in many shapes, both regular and irregular. Oval Opals, Round Opals, Tear Drop Opals and Freeform or irregularly shaped opals.
The brilliance or brightness of colour within an opal makes a big difference to the opals value. Brilliant, or gem stone quality opals, are far more valuable than bright opals. Opals also come in Subdued and Dull colours.