USE OF BASE BODY TONE GUIDE FOR BLACK OPAL

BODY TONE CHART
The body tone chart printed by the Opal Association has been well accepted but there ae some people who don’t understand it.The body tone refers to the darkness of a stone ignoring the backing or brightness of the stone
.A simple technique is to place the stone near the black squares and to compare the blackness of the stone by squinting at it.-this way the colour and fire don’t confuse you and you can see how dark the stone is and give it its proper rating..
As president of the Opal Association I get miners coming up to me and are angry at many internet listings as they feel it de values there product.
.A new Chinese buyer came in to Lightning ridge and remarked how dear opal is on the field compared to what research he did on the internet.
According to the Lightning ridge miners association field price and top bright black stone with multi colours [a N1 stone with a brightness of 5 out of 5] would sell for a app $1500 per carat.
The only N1 stones that should be at a lower price is blue-but a electric N1 blue should still be 100+ per ct on the field.

Many stones are listed on the internet with a N1 and Brightness rating of4/ 5 out of 5
Most of these grading would not be accepted on the opal field as such.
The body tone guide is a effort to make a level playing field so that buyers can compare stock between sellers.
A N1 with a top brightness that looks multi coloured and clean should be a GEM and not available cheaply as they are rare to find.
Only those stones with a N1 to N4 rating can be called BLACK OPAL

There are other factors involved in valuing a stone but the bae Body Tone is on of the most useful tools for helping a buyer on the internet.
The other factors include Brightness. Colour play –Patterns- Inclusions-direction of colour ect
iF ANY ONE IS CONFUSED OR WANTS TO MAKE A COMMENT PLEASE REPLY HERE

Last Update: 21 Jul 2010