Judith, if the lab grown stone is a true synthetic, then it, like natural
sapphire, is aluminum oxide. That is indeed a 9 on the mohs hardness scale.
Note that the term "lab grown" does not always mean the same thing as the term
synthetic, which would require the stone, if also labeled with the term
sapphire, to indeed be a true synthetic sapphire. Lab grown only means grown in
a lab. It's not a legally defined term, while "synthetic" as applied to gems,
is defined in FTC rules. However, most of the time, "lab grown" sapphires
purchased from major suppliers are indeed synthetic sapphires. Some ebay
sellers or the like, though, might play fast and loose with the terms.
As to the chip, there is a common misconception between hardness and toughness.
Hardness refers to the ease with which one material can scratch another.
Sapphire can scratch glass, but not the other way around, for example, so
sapphire is harder. But hard doesn't mean a material cannot be broken or
fractured. As an example, the sharp edge of a piece of glass can easy scratch a
piece of plastic. The glass is harder. Not drop both on a hard floor. The
plastic does not break, while the glass, more brittle and less tough, does
break. Another example: Diamond setters, using steel tools to set diamonds,
occasionally accidentally chip diamonds. The diamonds are much harder than the
steel, but the diamonds are not always as tough. Hit a diamond with a piece of
steel, the diamond breaks, while the steel gets scratched in the process.
Sapphire, while very hard as gems go, is somewhat brittle. Hit it wrong on an
edge, and you can chip it. The kitchen ceramic sink, or the bathtub, for
example, or a bit of a brick wall. Who knows. Lots of surfaces one might hit
the stone on are hard and rigid enough to transmit a sufficient shock to the
stone to chip it, even if those same materials are not hard enough to scratch
the sapphire.
If the chip is not severe, live with it. This is something that will happen
over time to most gems, even diamonds if worn long enough, especially if the
wearer also has diamond jewelry that might also bump the stone. You can replace
the stone, of course, but what happens when the owner again hits it by accident,
probably not even realizing she's done it, and it chips again. Wait until it
looks really worn, and THEN replace it. Or, if the replacement costs more than
maybe ten or fifteen dollars, you can have the chip recut and polished. Any
good lapidary that does facetting can do this. The stone gets another facet,
and then is slightly less symmetrical, but the chip is not then an obvious flaw.
Costs range, depending on who does the recutting and how much it needs, from
about ten dollars on up. A full recut of the entire stone restores all the
symmetry, but then the stone is smaller, and usually costs somewhere in the 30
to 50 dollar range, depending on the cutter, the complexity and size of the
stone, etc.
Hope that helps.
Peter
>On Sun, 10 May 2009 01:54:32 -0700, in rec.crafts.jewelry
>"Silverl...@aol.com" <Silverl...@aol.com> wrote:
>
<snip>
>
>If the chip is not severe, live with it. This is something that will happen
>over time to most gems, even diamonds if worn long enough, especially if the
>wearer also has diamond jewelry that might also bump the stone. You can replace
>the stone, of course, but what happens when the owner again hits it by accident,
>probably not even realizing she's done it, and it chips again. Wait until it
>looks really worn, and THEN replace it. Or, if the replacement costs more than
>maybe ten or fifteen dollars, you can have the chip recut and polished. Any
>good lapidary that does facetting can do this. The stone gets another facet,
>and then is slightly less symmetrical, but the chip is not then an obvious flaw.
>Costs range, depending on who does the recutting and how much it needs, from
>about ten dollars on up. A full recut of the entire stone restores all the
>symmetry, but then the stone is smaller, and usually costs somewhere in the 30
>to 50 dollar range, depending on the cutter, the complexity and size of the
>stone, etc.
>
>Hope that helps.
>
>Peter
What he said.
But as a jewelry restorer and repairman, I'd probably suggest simply
lifting the prongs, turning the stone so the chip is under a prong,
and pushing them back tight.
Ain't as much money in that for me, but you'd love me for it and
become a loyal customer. I could then later make up for it by gouging
you for some custom stuff.
--
Anulos qui animum ostendunt omnes gestemus!
>>But as a jewelry restorer and repairman, I'd probably suggest simply
>>lifting the prongs, turning the stone so the chip is under a prong,
>>and pushing them back tight.
Works OK with round stones. Not so well with ovals or other shapes...
:-)
Peter
Even if it is a 9 on the Mohs hardness scale (which is by no means
certain unless it is a synthetic Sapphire), that does not mean that it
cannot be chipped. Diamonds which are harder chip also.
In fact softer stones like Jade, are much harder to chip, because they
are much "tougher".
It is hard to say if the stone needs to be replaced or repaired, without
seeing the ring and the stone. In many instances a stone can be easily
repaired by re-cutting and re-polishing by a qualified stone cutter.
However, depending on the size and quality of the stone, that may cost
more than a new stone.
--
Abrasha
http://www.abrasha.com
Truedat Peter!
:-o
Doc, etc.
>
> Judith, if the lab grown stone is a true synthetic, then it, like natural
> sapphire, is aluminum oxide. ?That is indeed a 9 on the mohs hardness scale.
> Note that the term "lab grown" does not always mean the same thing as the term
> synthetic, which would require the stone, if also labeled with the term
> sapphire, to indeed be a true synthetic sapphire. >
Before I bought it, I did ask if it was the kind that is identical
chemically, optically and physically to natural sapphire, and was told
that it is, so it better be.:-)
> ............Hope that helps.
>
Yes, that was very helpful.
Thanks!
Judith
I wish I could, but it's an oval and the chip is on the long side. I
will definitely remember this for future use, though!
Thanks,
Judith