Feb 202015
 
Figure 1: Solid opal or opal doublet (composite)

Solid opal or opal doublet (composite)

Admin: Alan Hodgkinson is a Special Guest Author for the AIJV.  Here, Alan explores a tricky opal doublet.

It would certainly make life easier for the gemmologist/ appraiser if all composite gems were claw set, or even better if loose (unmounted) – wishful thinking of course. In such situations, the doublet joint is so easy to see.

Life was never meant to be so straightforward and there are situations where the junction plane of a doublet is concealed by a collar setting (figure 1). The pendant shown (Figure 2) provides a good example of the problem.

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Nov 262010
 
Green sapphire crown and a synthetic ruby pavilion

Figure 1

Admin: Alan Hodgkinson is a Special Guest Author for the AIJV. Here is an excerpt from his soon to be released book ‘Gem Testing Techniques’

Nothing could be easier than to identify a gemstone as a composite (doublet or triplet) when confronted by a loose gemstone.  A view of the junction plane will normally reveal the dual component quite easily, regardless of the skill of the maker of such counterfeit gemstones. Continue reading »