How are opals valued?

Answer 1

Black opal can be very expensive, only low grade black opal is sold by kilo weight. This low grade is called potch and colour which means that maybe bit of colour might be in this rough black opal I have seen parcels sold for $200 per kilo but it has no colour. Good kilo bucket of rough black opal would cost around $5,000 .00 Black opal is rated by body tone N1 for deep black colour, and N4 for light black colour. So for $5000 per kilo, dont expect N1 body tone. Black opal is sold by carat, and rare patterns are worth $5,000 to $20,000 per carat; especially red fire harlequin pattern n1 body tone, and over brighness rating of 4.

Answer 2

HK$980