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Diamond trick


#1

Hi
would like to ask if theres any simple trick to determine a real
diamond when inspecting a ring sometimes really old rings other than
using a diamond tester. thanks mike


#2

Mike, my teacher doesn’t takes in a diamond ring for repair unless
the customer allows him to run a cratex wheel over it while the piece
is still in the customer’s hand. Cratex will scratch and dull CZ just
like it does into metal but won’t dull diamond. He says that he’d
rather replace the $3 CZ than have a customer charge him with stealing
a nonexistant diamond. Geo.


#3

Some “tricks” I learned while going through GIA was to exhale hot
breath on a clean stone. CZ and some other simulants will fog up for a
longer period of time as opposed to a diamond. Also, most simulants are
easier to see through from the pavilion. If you put a cz down on a
piece of paper with type on it, the letters are more visible than
through a diamond. One moRe: look for rounded facet edges. Diamonds
hardly ever have rounded edges. One of the best indicators of a
diamond is it’s high luster. Then there is the ink test where ink
(india) will make an unbroken line on diamond; where it will bead up
on most simulants with a high R.I. One more histerical test that
really doesn’t apply to diamonds is: to place the stone against your
cheek. If it feels cool, then you know it is at least a crystal. If it
feels warm then it is most likely glass or plastic (amorphous). It is
funny to watch the customer’s expression when you tell them that you
are doing some “high tech” tests on their stone. None of these are
definitive “tests” to identify stones but can be helpful in the
process. Ken Sanders GG


#4

Geo., Maybe if your teach does’nt mind spending $3 for a cz(not to
mention his time for setting it)he could save all those three dollars
and buy himself a diamond tester they are real economical now days.
Best J Morley Coyote Ridge Studio


#5

Hi Orchadians what about ionic attration where you put the diamond on
a piece of glass, on the pavilion and push it against the glass while
moving it forward … it will stick to the glass fairly securely…
ringman John


#6

Geo,What I do to quickly check a stone that is questionable, is take
a metal scribe or awl and find an inconspicuous place and try to
scratch or mark it. If is a CZ it will mark, though it may take a 10X
loop to see properly.That way I don’t have to do any uneccesary resetting.
Thomas


#7

Hi,

  Hi Orchadians what about ionic attration where you put the
diamond on a piece of glass, on the pavilion and push it against the
glass while moving it forward ... it will stick to the glass fairly
securely...

I don’t think the force that causes the diamond to sitck to glass is
necessarily an ionic attraction. If you rub 2 pieces of anything that
is really flat together, they’ll stick. I’ve done it with 2 pieces of
plate glass & 2 pieces of steel.

Dave


#8

Scratching any stone is considered a destructive test. It is the
wrong thing to do. Yes, people like to mention a diamond’s hardness
–and as a proof of it use scratch testing.

You should consider other gemoogical means to determine whether or
not it is a diamond incliuding the use of a microscope to study the
girdle and facets, whether or not it is singly or doubly refractive,
etc. If you have no gemological background, there are plenty of books
to guide you in that area. You van also purchase a diamond and
moissanite tester and use them together to weed out moissanite and
other simulants.

Good luck!


#9
ike, my teacher doesn't takes in a diamond ring for repair unless
the customer allows him to run a cratex wheel over it while the
piece is still in the customer's hand. Cratex will scratch and dull
CZ just like it does into metal but won't dull diamond. He says that
he'd rather replace the $3 CZ than have a customer charge him with
stealing a nonexistant diamond.  

Comeon guys, CZ’s usually cost more than $3.00!!! A diamond tester
would be the better choice. I’m sure a customer wouldn’t like to
have their CZ (no matter what it costs wholesale- that they have paid
a bundle for) ruined.


#10

I think the point here is: but would the customer believe the
diamond tester? If the customer believes he has a diamond, I doubt
that the results of a “tester” would convince him. Whereas the Cratex
test would be completely undisputable. Margaret @Margaret_Malm


#11

John I’ve been sticking cublic zirconia on the under side of glass
display cases for at least 15 years - the process is called “wringing”

  • any two hard really flat surfaces will do this - in particular I
    remember in inspection, using glass guage blocks that had the same
    effect, I seem to recall that 1 inch optical flats will hold
    thousands of pounds and must be moved side ways in a "shearing"
    action to be separated - think if it as a non movable suction cup -
    has more to do with air pressure than with ionic attraction I believe
    Russell htp://www.RussellsofCamden.com

#12
    I don't think the force that causes the diamond to sitck to
glass is necessarily an ionic attraction. If you rub 2 pieces of
anything that is really flat together, they'll stick. I've done it
with 2 pieces of plate glass & 2 pieces of steel. 

-in the interest of science…and only science—i will be happy to
test the diamond…could you please send me a 2carat stone, maybe 3,
i need to see it well to conduct the theory…and i have such bad
eyesite…

and to try to behave now, i have had some time to work on new designs
and have a couple at this site, any feedback would be wonderful…

pat


#13

If a scratch or other potentially destructive test is performed on a
diamond that has inclusions near the surface, the diamond can chip.
If the scratch test is done in a manner that puts pressure along a
cleavage plane, a diamond can chip. I have seen several diamonds
over the years that were damaged by this means of testing.–One wasa
5 carat stone that the jeweler didn’t belive was real since it was so
large and such a good quality. It cost him $14,000 in lost value
when the stone was recut. He could have had to replace the stone–he
was lucky that the owner accepted it as recut with payment for loss
in value. What if the gem is not a diamond and not a cz, but some
other stone that is not $3? Replacement could also be expensive.


#14

If One inch optical flats wrung together will hold more than a 14
pound load, then it’s not an air pressure or vacuum/suction cup
effect. One one inch pieces, that 14 psi of atmosphereic pressure
represents the maximum possible holding force the atmosphere could
exert…

Peter


#15

hi: In My experiance I have never been able to get a cz to stick to
glass in that fashion… go figure…ringman


#16

I think the point is that an item that belongs to a customer has to
be treated with respect. Wouldn’t it be better to tell the customer,
“sorry, this isn’t a diamond”, and let them go away with their
jewelry intact? Its much better than destroying their property and
giving them reason to dislike your establishment.


#17

In a case where the owner believes the stone is a diamond and the
jeweler believes it is not, the logical action is simply or the
jewelry to refuse to take the job. If they dont believe the ‘diamond
tester’ then they are not likely to believe the ‘cratex test’ either.

Michael / QuestFox


#18

My understanding is that this is definately not a good test. In my
readings I came across a case that demonstrated the problem with
this. The person involved inherited a stone without an explanation as
to what it was, just a clear stone in a safe deposite box. why they
took it to a pawn shop I dont understand. the owner of the pawn shop
took a carbon steel scribe and made three small 'X’s on one of the
facets, and expalained to the owner of the stone that the stone was
too clear for a stone of that size to be a diamond and that diamond is
the hardest known substance and could not be scratched. The same
properties that make diamonds hard also make them easy to chip or
scrach in relation to thier hardness. Later the owner of the pawn
shop was sued for having damaged a very large, high quality diamond.
Michael


#19

I couldn’t agree more. Think of it this way. Suppose you take in
the job, and nothing happens. You’ve told the customer it’s not a
diamond, but they don’t believe you. The next guy who see the stone
might agree with you, and tell the customer that it isn’t a diamond.
This time they believe it. But you where the last one to have the
stone. If I’m a judge of human nature (actually, I’m just a cynical
old bench jeweler of 27 years in the field) they are going to
conclude that you were the one who switched the stone, rather than
good-ol-Joe-jeweler in their home town who sold it to them Maybe Joe
didn’t know either, but you are likely to be the goat in this one.
It’s a case of “shoot the messenger” and why even take a chance on
being in the line of fire? It’s a litiguous world out there, and one
might be advised to cover one’s hiney.

This is what we in the trade get for having spent centuries
downgrading the value of our workmanship while convincing people of
some intrinsic value of materials to get our price. Someone tell me,
what are we jewelers going to do when science learns to make gold and
diamonds as cheaply as they make plastics today? Was a time when
aluminum was more valuable than gold, you know…and early plastics
were pretty pricey too.