Was: Turquoise doublet
Opals and opal doublets are valued as separate entities. An
adjustment to value based on whether there is backing or not is a
valuation relic left over from real estate methodologies and
questionable retail practices. The differences in backed and
nonbacked opals are so varying that a formula does not due it
justice, nor is it remotely accurate.
This is valuable I'd really like to hear more about
this from appraisers and cutters.