[Jewelry making - Article 00618] - Re: [Orchid] Gemological instruments

[The Doctor]

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>         I am planning to start out in Gemological studies and wondered
>     if any of you would have some tips on buying RELEVANT instruments.
>     I am on a budget 

    You'll need a good gemological refractometer to measure refractive
    index (RI), but good luck finding one on a budget. Fair deals can
    sometimes be found on eBay, but buying a used one sight-unseen that
    has a scratched hemicylinder will just make you cry. A new GIA
    refractometer lists for around $660 US. There are less expensive
    refractometers out there that are not bad for flat facet readings,
    but they don't work as well for spot reading cabochons. If you don't
    know what that means, trust me - you will, eventually. RI
    measurement is arguably the most important clue in gem ID, as is
    birefringence. I suggest you buy the best one you can afford. 

    A good gemological microscope with darkfield illumination is another
    necessity. It would be nice to have a zoom model, but I've gotten by
    with an inexpensive GemOro 10X, 30X quite nicely. I'd trade a lot
    for a nice 10X - 64X zoom, though. Many get through GIA'a Gem
    Identification program with a 10X loupe, but you'll do much better
    with a microscope. You can find the GemOro all over eBay for around
    $300 US 

    A polariscope is a must, also. Fortunately, you can get by with a
    couple of polarizing lenses from a cheap pair of sunglasses and a
    light source. You'll need one to determine optic character, etc. 

    A calcite dichroscope also comes in handy, as does a Chelsea filter. 

    An accurate gem scale to determine specific gravity. A lot of people
    use SG liquids for this, or both, as I do. Also, there are balance
    scales specifically geared to measure SG. SG is a valuable clue for
    gem ID, nearly as valuable as RI. 

    Also consider a Longwave/Shortwave UV light. They can help make a
    lot of separations. 

    There are plenty of other things you will eventually want, but this
    is the short list of what I consider to be absolutely necessary to
    begin the study of gemology. Once again, I'd recommend getting in
    touch with: 

    Hanneman Gemological Instruments
    PO Box 1944
    Granbury, TX 76048

    Available there are inexpensive SG liquids, microscopes, the famous
    SG balance scale, loupes, dichroscopes, spectroscopes, some very
    useful gem filters, etc. However, I do not recommend the RR
    Refractometer. While it may be a useful indicator of a gem's nature,
    it isn't sufficient for serious beginning gem ID study, in my
    opinion. 

    Also, go to Ganoksin's Jeweler's Selected Bibliography and search
    "gem identification." The URL:
    http://www.ganoksin.com/jewelry-books/index.php Every book on the
    page is worth purchasing. 

    One of my favorite web sites has an intro page for aspiring
    gemologists with an open offer to download any of the info for
    personal study. To the left of the page are studies of most of the
    equipment I've listed above. Check it out: 

    http://www.yourgemologist.com/studyofgemology.html 

    Best of luck to you in your studies, 

James in SoFl

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