[Jewelry making - Article 00010] - Re: [Orchid] Synthetic amethyst

[Rick Martin]

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>          In my experience, the quickest way to spot synthetic quartz
>     is to check for black light fluorescence. 

    Upon reading this I checked my entire amethyst inventory, including
    several known man-made cut stones as well as Russian hydrothermal
    rough.  Result: no fluorescence in either natural or synthetic.  I
    checked carefully under both long and short-wave.  I was disappointed
    because I'd hoped this might be a simple solution to an irritating
    problem. 

    I don't dispute that there may be fluorescent synthetic quartzes. 
    Colored varieties of hyro quartz have been around since approximately
    1970.  Many companies around the world have grown them for gems,
    using  additives to achieve the desired colors before color centers
    were well understood. It's very possible some additives cause
    fluorescence. My little test demonstated that the lack of
    fluorescence does not prove natural origin for amethyst. Neither does
    the presence of twinning. 

    Learning to recognize natural inclusions and especially color zoning
    in amethyst (as Steve Green has explained in detail) may be the best
    way at present for jewelers to distinguish between the two. Some time
    back I recall reading that the AGTA gem lab had a reduced-cost
    program to screen parcels for large amethyst users.  I think the GIA
    may have a similar program. I don't recall the tests they use but
    they're more sophisticated than those available to small gem labs. 

Rick Martin
MARTIN DESIGNS

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