[Jewelry making - Article 00280] - Re: [Orchid] Naming gem materials

[Peter W . Rowe]

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>            You certainly make startling statements here; in my 40
>     years of lapidary I never saw a "scratch" to appear on corundum
>     unless there was an imbedded foreign mineral there. 

    Ask any stone setting whether they've ever noted a ruby or sapphire
    to  develop an unfortunate "scratch" just above the edge of a bezel,
    if they were too aggressive with a graver or burnisher.  I've done
    enough of those  scratches myself to know this happens.  In actual
    lapidary work you're not so  likely to have the problem, since you're
    not generally pushing so hard with a steel point. Trust me, my
    friend, it happens. Anything but diamond, you can damage if  Mr.
    Murphy's laws decide to take hold, and you're not careful.  Harder
    stones are harder to damage, but not impossible.  

>        And quartz will easily scratch with good steel. 

    Well, yes.  I said the same, in essence, above, where I point out
    that  even sapphire or ruby can, in some instances, appear to be
    scratched by steel. So didn't you say jade would resist that scratch?
     Jade, both nephrite and  Jadeite, are both SOFTER than quartz.  But
    they are tougher.  You might have to  press harder...   if your steel
    will actually scratch the quartz,  then the  same steel will surely
    scratch jade.  I still maintain that a hardness test with  your
    trusty pocket knife, as you suggested, is not a good and reliable
    proof  of jade. Sure, it easily makes some separations,  but your
    statement was a lot  more of a blanket one than that.  And I'll stand
    by my statement that, in agreement with a number of gemological
    authorities, using hardness tests on finished cut  gems is a poor
    practice to be discouraged when possible.  

>       And a needle is sufficient to make the test on a small bead with
>     no apparant damage to the piece. 

    why do any damage at all?  And though a bead may be easy to find
    some inconspicuous spot to test, I promise you that if you plan to
    use a  hardness test on really good quality jade, even a small
    scratch could land you in  a courtroom.  Sure, your bead won't do it,
    but the needed tests are not  that complex, and apply equally to the
    25 cent bead as to the 25K imperial  jade cab. 

>       'Guess I just don't understand those who complicate every little
>     matter. I've succeeded in this profession by usually sticking with
>     my favorite philosophy: 'keep it simple'. 

    I'd point out that when you stick with keeping it simple to test
    your  jade, you are relying on MUCH more than just the hardness test.
     You're also  relying on those 40 years of experience with jade, it's
    appearance and nuances.   Perhaps you're not giving your eyes enough
    credit, but you're seeing much  information that helps you know what
    you're seeing long before pulling out that  needle to check that one
    last factor.  This works fine for you, with the experience to know
    what you're seeing.  But posting to the list saying that all that is
    needed is the hardness test, might lead some neophyte to think that
    they, with  no experience with jade, can use hardness with equal
    surety.  And that just  isn't the case.  

    I don't suggest complicating anything beyond what is needed.  Keep
    it  simple works well, when it's appropriate.  It's common knowledge
    that people  with enough experience can, by eye alone, identify most
    gems.  They're using  the appearance of many factors of gemology, and
    though they're not doing  formal tests, they're looking at the
    results those properties impart on the  appearance of the gem.  that
    takes nothing more complex than knowledge and practice  and knowing
    what to look for.  After all those years, whether you realize it  or
    not, your eyes are enormously sophisticated testing instruments, as
    are your  hands, knowing the feel of the stones.  When, for example,
    I say a steel graver  can scratch a sapphire, I'm not implying the
    steel is harder than the  sapphire.  I'm pointing out that not all
    scratches are quite the same, and without  practice, the test can be
    confusing.  Someone determined to scratch a stone with a  steel tool,
    usually can succeed, even if the stone is harder.  And some harder 
    stones are brittle enough that causing damage with a steel tool is
    downright  easy.  Any stone setter will confirm that for you. 

>      And you can't take a $10 "jade" necklace to a gemologist and pay
>     $25 for an academic ID just every day...(Which you'd be forced to
>     do under your suggested protocols). 

    No, you're not forced.  if you learn the proper testing methods, you
    can  do it yourself much more easily, in only a little more time than
    that scratch  test, and without potential damage, even small, to the
    stone..  My point is  just that your blanket statement that all you
    need is a pocket knife, while true sometimes, is just too broad a
    statement. 

    Knowledge is power, it's been said.  Gemological training can be had
    from many sources, both costly and formal, or almost free, if one
    takes the time to find the books and study them.  Once upon a time, 
    homebrew methods and simple wisdom were fine.  Nowadays, a bit more
    sophistication is in order.  Among other things, the gem market has
    gotten a lot more sophisticated in terms of  the fakes and frauds and
    stimulants offered for your consumption.  Some are very  good
    duplicates indeed.  It is well worth the time to be informed and
    able to determine what one is dealing with, as well as willing to
    "punt" when a situation demands more equipment or skill than one has
    available. 

Peter

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