Value of Opal Jewelry

The value of Opal:
     The value of an opal depends on many things - the body tone of the opal, the brilliance of it, the pattern, colour bar thickness, faults, and the play of colour. It is generally examined and given a price per carat. As well, cut and polish and the size of the stone are important.

Body Tone: Body tone is one of the most important factors in opal value. It refers to the background or the "underlying" colour of the opal which can range from dark to light. Generally, those with a black or dark body tone are more valuable than those with white, light or crystal body tones. Black opal from Lightning Ridge is the most prized opal and can be sold for prices of over $10000 per carat.

Opal colours are classified as follows:
- N1, N2, N3, N4: Black Opal
- N5, N6: Dark Opal
- N7, N8, N9: Light Opal

     Crystal opal refers to the transparency of an opal - not its structure. It is any type of opal that is translucent to transparent.

Brilliance: This refers to the colours displayed by opal, when it is viewed face up. This ranges from brilliant, bright, to subdued or dull.

Pattern: The pattern of coloured segments, forming the play of colour (see below), is unique to every individual opal. The distinctiveness and colour displayed by these segments determines the quality of the pattern of an opal. Some patterns you may find on opals include: Harlequin (highly sought out), Flagstone, Straw, Chaff, Chinese Writing, Floral, Rolling Flash, Broad Flash and Pinfire. Poorer patterns are indistinct and the patterns are called Moss and Grass.

Colour Bar: The thickness of the colour bar in opal is relative to the overall size and shape of the individual stone. This should be taken into account when valuing the stone, but makes little difference to appearance once set in jewelry.

The Play of colour: This is the brilliant array of colours caused by the diffraction of white light on the internal structure of the orderly arrayed spheres of silica. Red (fire) opal is more valuable than mainly green opal, which is more valuable than blue opal. Nature does not produce the red colour as often as it does the blue or green. The red colouring is caused by larger microscopic silica spheres, the blue by smaller ones.

Faults: Faults that may detract from the value of the finished opal include the following:
- Cracks: A crack in the face of an opal can render it almost worthless.
- Crazing: This is many small cracks in the opals face, will make it worthless.
- Sand: or various other minerals can be found included in or under the colour bars of the opal.
- Pock Lines
- Webbing (grey lines)
- Windows
     When purchasing an opal look for the above mentioned factors and make sure that the opal you buy comes with a certificate of authenticity.

Related Links:
opal-jewelry/index.html
opal-jewelry/care.html
opal-jewelry/genuine.html