Valueing opal is a tricky thing to do, but first work out which category you opal may fit into

Gem

•distinct patterns of colour
•bright vivid colours
•multicoloured bright flash
•used in high quality jewellery
•investment gemstones

Commercial

•strong colour
•blues / greens
•multicoloured bright flash
•used in fine jewellery
•high value

Matrix

•ironstone speckled / streaked with opal
•quality of colour can vary
•all jewellery lines
•broad market

Potch

•opal with no living colour
•milky, clear, brown grey - opaque
•carvings, ornaments
•low value
 

Ironstone

•host rock of opal
•swirling sedimentary layers
•carvings, ornaments