Colour, Patterns & Value

Over many years there has been guidelines developed on how to value Opal. We are going to explore the factors that contribute to an Opals final value. These factors are:


Color is the first thing that you will notice about an opal. Red is the rarest and most sought out color. In order of value, the most valuable color is red, then orange, green, blue and purple. However, Opal is usually never a single color. It is important to decide what the dominant color is followed by any secondary colors. Use the dominant color as the color that will affect the price.

Direction of Colour

Opals are a gemstone that dramatically change appearance based on what angle the Opal is viewed at. When an Opal is at it’s brightest, this is called ‘facing’.


Opals that have a rare or unique pattern are more valuable. The Harlequin pattern is the rarest and most loved pattern in opals but it is very rare.  Some top patterns are Mackerel, Block, Broad flash, Rolling flash, Pinfire, Rainbow and Honeycomb pattern.

Body Tone Guide

The Opal Body Tone Guide was endorsed by the Opal Association of Australia and was intended to be a guide for Black Opal and Boulder Opals. It is now generally excepted for all opals worldwide.


The Opal brightness guide was produced by the Australian opal association along with the body tone guide.


Precious opal is usually cut into oval, pear, or round shapes. Occasionally, other shapes are cut including marquis, rectangle and heart. Non-standard shapes include freeform and baroque. Shapes which will produce difficulty for the jewellery setter will often decrease the value of the stone.