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Irradiated stones??



 
 
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  #1  
Old January 4th 05, 09:43 PM
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Default Irradiated stones??

I bought a blue topaz online at Ice.com and it's amazingly blue.
I was told that most Blue Topaz is usually irradiated? Is this true?

What about stones like Peridot, Amethyst, or Moonstone?

(Particularly those in jewelry made in Nepal, etc for instance? )


This practice seems a bit unhealthy to me. Even though some claim these
are "safe"levels, any "level" of that would seem dangerous to me. How
is this done exactly and how much radiation is usually in these and if
worn for a short time, could this cause a health problem?

Any more info on this "irradiation" thing, or any links anyone knows
of, will be greatly appreciated.

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  #2  
Old January 5th 05, 12:26 AM
Carl 1 Lucky Texan
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irradiated to turn brown first, then heat treated to blue. same process
as occurs in the ground - just done in a lab instead. Unlikely to be
dangerous even if swallowed and retained in the body - much less so if
worn occasionally aroun the neck for a few hours. HOWEVER - there were
some chrysobeyyls that came probably from China a few years ago that
violated US NRC standards for residual radiation - still though,
probably not more than getting an xtra chest xray a year or a sunburn.

check;
http://www.yourgemologist.com/irradiation.html

Carl
1 Lucky Texan


wrote:

I bought a blue topaz online at Ice.com and it's amazingly blue.
I was told that most Blue Topaz is usually irradiated? Is this true?

What about stones like Peridot, Amethyst, or Moonstone?

(Particularly those in jewelry made in Nepal, etc for instance? )


This practice seems a bit unhealthy to me. Even though some claim these
are "safe"levels, any "level" of that would seem dangerous to me. How
is this done exactly and how much radiation is usually in these and if
worn for a short time, could this cause a health problem?

Any more info on this "irradiation" thing, or any links anyone knows
of, will be greatly appreciated.


--
to reply, change ( .not) to ( .net)
  #3  
Old January 5th 05, 02:32 AM
C. Gates
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wrote:
I bought a blue topaz online at Ice.com and it's amazingly blue.
I was told that most Blue Topaz is usually irradiated? Is this true?


Yes, particularly for the very strong blue. But the word "irradiated"
does not mean that the stone is radioactive.

What about stones like Peridot, Amethyst, or Moonstone?


Virtually never. Not an issue. Zircon is sometimes naturally
radioactive, but I won't go into that. Evidently, amethyst and smoky
quartz get their color via radiation, and with natural stones, from
radiation from surrounding rock through millions of years. (More on
natural rock later in the post.)

(Particularly those in jewelry made in Nepal, etc for instance? )


Why Nepal? It's not the makers of the jewelry, it's the processors of
the stones. Nepal as a country of origin per se is not an issue.

This practice seems a bit unhealthy to me. Even though some claim these
are "safe"levels, any "level" of that would seem dangerous to me.


In that case, when you travel, you should consider driving, or taking
trains and boats, to avoid doses of whole body radiation that you get
aboard jet aircraft, especially on longer flights, when you are above
much of the earth's protective atmosphere for hours at a time. Plots of
radiation are on the web. You'll be surprised!

How is this done exactly and how much radiation is usually in these and if
worn for a short time, could this cause a health problem?


Details on the irradiation process and government requirements for
levels are easily found through a search on the web. I recently had a
customer return a piece of jewelry containing a 10mm blue topaz a year
after she bought it because she read that it had been irradiated and she
assumed that it was dangerous. It showed no radiation above background.
We offered her an immediate refund, which she declined.

The next day, we checked the other stones in the parcel her stone came
from with our geiger counter -- on the chance that they might have
slipped past government inspections, etc. The stones had the same
background reading as background -- in other words, no detectable
radiation. I called GIA and AGTA labs to check on what they did.

Out of curiosity, we walked around the shop looking for something
radioactive. And we did find a couple of things that were slightly
higher than background. One was a large granite boulder that is part of
the foundation of the shop. Has been there since around 1820. Brought to
town by the glacier some 30,000 years ago. Barely detectable radiation,
probably from thorium or uranium with a long half life. And probably
emitting its share of radon, too, no doubt. The other "hot" stone was
one particular piece of petrified dinosaur bone from Utah. Again,
probably from traces of natural uranium. Expected a bag of trinite to
peg the meter, but negligible results from that, too. (Trinitite is soil
fused to glass under the first nuclear explosion, which took place in
New Mexico. It's a slight alpha emitter, but that's another story.)

The "cooling off" period for irradiated topaz can be up to a year before
it declines to the point where it will pass government safety
inspections. Add to that the time in the pipeline from cutter through to
consumer, you might add another year or more for ever further diminishing.

All in all, you experience many health risks and never know it. Radon is
a common one. Arsenic in drinking water is a under-rated hazard, maybe
because it is so widespread throughout the country. Check that one out!
Low does of arsenic are really bad for your health. As a health risk,
it's a real sleeper. Blue topaz belongs way, way down on the list of
things that can be potential health risks.

But, if you're worried about it, have it checked.

  #5  
Old January 5th 05, 07:16 AM
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Thankyou for all of the replies.
Very interesting stuff.

How about Amber? Is Amber ever irradiated? How is that treated?

What's the difference between "heat treated" and "irradiated"? Does
heat treatment involve radiation of any sort?
I had read that the two are similar, though it didn't make much sense
at first. I'm new to all of this and a little slow about things like
this.


So, as for Moonstone and Peridot... it's pretty much never used? If
not, how are these stones usually enhanced? As in peridot's to look
greener or darker or more coloration, or moonstone do give more of the
blue streak effects, etc.?

  #6  
Old January 5th 05, 07:56 AM
Peter W.. Rowe,
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On Tue, 04 Jan 2005 22:18:19 -0800, in ?? wrote:

Thankyou for all of the replies.
Very interesting stuff.

How about Amber? Is Amber ever irradiated? How is that treated?


there are a number of ways in which amber is treated. the most common is a combination
of heating and pressure. Amber is, of course, a resin with fairly low melting point,
so by heating it to near it's melting point under pressure, small imperfections and
bubbles can be made to diffuse or otherwise disappear, thus making cloudy amber appear
clear. Variations of the treatment include heating it while under certain oils, or
heating it enough to actually melt, combining small pieces into larger ones, or
imbedding fragments of amber in a matrix of a similar synthetic resin. The most common
heat treatments leave the amber clarified, but not actually "flowed", preserving some
natural looking inclusions, but causing stress fractures in some others. The result are
characteristic "sun spangles", or small disk shaped fractures within the amber that can
actually be quite attractive sometimes. Note that not all amber is treated. Much of
it, especially the material from the Carribian/Dominical republic, which often occurs
quite clear already, is not treated. Most amber treatments leave quite characteristic
looks or markings, so are usually fairly easy to identify. Perhaps the biggest quandry
when working with amber, from a consumer's point of view, is not detecting treatments,
but just telling whether a piece actually is amber at all, in the first place. A number
of non-fossil resins, such as copal, as well as some synthetic materials, can closely
resemble amber.



What's the difference between "heat treated" and "irradiated"? Does
heat treatment involve radiation of any sort?


Um. I'll restrain myself on this question.. (grin).. Heat treated is simply heating.
Sometimes it involves heating in a specific environment, such as an oxidizing or
reducing environment, or while immersed in some specific chemical, or the like. But
heat treatments is basically just putting the stones in an oven of some sort, gently
heating to specified temps, and then gently cooling. In some stones you can do it with
a toaster oven. Others, needing higher temps, require much more sophisticated setups.

Irradiation generally involves exposing the stones to some type of nuclear radiation.
"There are several types, some inducing radioactivity in the stones, others not, which
also varies from stone to stone. One of the most common procedures involves simply
placing the stones alongside certain strongly radioactive materials. And early version,
used to turn diamonds green, simply put the diamonds in close proximity to radium salts,
a process that left those stones strongly radioactive, for periods of years (It's not
done any more, fortunately, as now, other radiation sources are available that nicely
change the color without making the stones radioactive). A modern safer version of this
involves putting the stones in what's called a "gamma cell", simply a container
containing highly radioactive isotopes that emit gamma radiation. The resulting
radioactivity is much shorter lived, so by the time stones reach the public, they are no
longer radioactive. Another method exposes stones to a high energy electron beam, a
procedure that requires much more involved equipment to generate, but doesn't induce
radioactivity. The exact nature of an irradiation treatment used with any given stone
depends on the physics of what the treatment is trying to do, since different
irradiation methods will have different effects. Overall, these treatments are quite
similar to the ways irradiation is used in other ways, such as cancer treatments, by the
way, though irradiation of gemstones sometimes can involve much higher energy levels
than medical irradiation.

In scientific terms, there are more similarities between irradiation and heating than
there are differences. Both expose the stones to types of energy or particle
bombardment at elevated energy levels. In terms of heat, the particles are photons, the
same as visible light but at the longer wavelength of infrared, which is heat.
Irradiation treatments have a number of types of particles that can be used to transfer
energy to the stone, including high energy electrons, gamma rays, alpha rays, beta
rays, or combinations. All of these are found not just in the lab, but also in nature,
in sunlight (solar radiation), and in the general levels of natural radiation around us.

For the stones, however, the effects of different types of radiation versus heating are
often quite different. heating is a low energy thing. The effect of heating can be
thought of as loosening the atomic bonds in the material, making atoms more mobile in
the crystal structure. That, just as in the way it can be used to anneal the stresses
in worked metal, or allow distorted crystals from cold working in metal to literally
reform and recrystalize, can also allow atoms in a gem material to move around a bit,
fixing minor defects in the structure, allowing some mobile elements to diffuse into the
structure (such as oxygen, for example, which can then combine with some other materials
forming oxides, which often change the color of a material), or to literally heal
certain types of damage on the molecular level.

Most irradiation treatments involve much higher energy levels in the particles used.
Generally, these treatments work not by "annealing" stresses or damage, but instead by
causing them, knocking electrons out of their normal energy levels in atoms, or changing
the atomic structure of a crystal to create "holes" where electrons are now missing, or
otherwise changing changing things around. These changes then affect the way light,
passing through the stone, is affected by the stone, thus changing the color.

The two treatments are often combined, one after the other. Commonly, irradiation is
used first, which often induces too much of a change, or a change to an unattractive,
often dark color. Careful heating then can sometimes be used to relax the irradiation
caused atomic damage to a specific desired state, which then is the desired color.

I had read that the two are similar, though it didn't make much sense
at first. I'm new to all of this and a little slow about things like
this.


There are many misconceptions about just what irradiation is, as well as many other
matters regarding physics and nuclear reactions, nuclear radiation, and the like,
starting with our own President's inability to even pronounce the term correctly. (It's
NOT "New kuw ler", but "New klee er") From a physics standpoint, heating is a form of
radiation. From a gemological standpoint, and the standpoint of what each does to a
gem, there are clearer differences.



So, as for Moonstone and Peridot... it's pretty much never used? If
not, how are these stones usually enhanced? As in peridot's to look
greener or darker or more coloration, or moonstone do give more of the
blue streak effects, etc.?


Neither treatment is generally used with either stone. Both generally are used just as
dug up. I think some types irradiation may be used with one specific type of moonstone,
the so called "rainbow" moonstone, which shows flashes of multiple colors almost like
crystal opal, but I could be wrong on that. For the more common moonstones, and as
regards the intensity of the blue or white "flash" effects, those are not due to
treatments, nor readily affected by treatments. Some stones do it well, others don't.
It IS needed to carefully orient the direction of the rough stone when cutting, as these
effects are highly directional.


Peter Rowe
  #7  
Old January 5th 05, 09:23 AM
vj
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vj found this in rec.crafts.jewelry, from "Peter W.. Rowe,"
:

]Neither treatment is generally used with either stone. Both generally are used just as
]dug up.

**smile**
the jeweler i'm apprenticing with commented that "unless you dug the
stone out of the ground yourself, or know who did, odds are it has
been treated *somehow* before it got to you. these days, it's very,
very difficult to find stones that have not been treated, especially
if you're buying them for jewelry. one more reason i'm not really
interested in being that kind of jeweler, and for belonging to my
local rock club!


--
@vicki [SnuggleWench]
(Books) http://www.booksnbytes.com
(Jewelry) http://www.vickijean.com/new.html
(Metalsmithing) http://www.snugglewench.com
yahooID: vjean95967
-----------
"Only Irish coffee provides in a single glass all four essential
food groups: alcohol, caffeine, sugar, and fat." -- Alex Levine
  #8  
Old January 5th 05, 10:07 AM
Peter W.. Rowe,
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On Wed, 05 Jan 2005 00:25:18 -0800, in ?? vj wrote:


]Neither treatment is generally used with either stone. Both generally are used just as
]dug up.

**smile**
the jeweler i'm apprenticing with commented that "unless you dug the
stone out of the ground yourself, or know who did, odds are it has
been treated *somehow* before it got to you. these days, it's very,
very difficult to find stones that have not been treated, especially
if you're buying them for jewelry. one more reason i'm not really
interested in being that kind of jeweler, and for belonging to my
local rock club!


While your statement is certainly true in general with stones these days, as it happens,
peridot in particular, and moonstone also in most cases, happen to be stones for which
useful treatments do not yet exist, at least in terms of the treatments such as heat
treatment or irradiation for color improvement. Thus those two generally can be
trusted to be untreated. One must, of course, still make sure that your peridot is
indeed peridot rather than some imitation or other similar stone. As a general rule,
the feldspars as well, (moonstones) are not improved by this type of treating, though
some porous types can be dyed, and one might find things like a surface laquor or wax
used with or even instead of a conventional polish on the surface. And both perodot or
moonstone, if found with fractures and flaws, might be oiled ot otherwise resin treated
to help hide those fractures. With peridot, however, this is still unlikely, since the
stuff even without fractures is fragile, and oiling or fracture filling does not
increase the strength of a stone, so peridot with enough fractures to benefit from
fillings, probably wouldn't survive long enough to make it through cutting, or to
market. This is only likely an issue with low quality cabochon cut peridots, not
facetted ones, and even then, it's a marginal treatment at best. Not at all common.

So by the time we're done with that, in general, you can probably trust your peridot and
moonstones to not be treated in any really signficant way. If there's a little wax to
help the shine on the moonstones, who cares. Only the really cheap porous ones need
that, and they don't look like anything much more costly when it's done. . If that
moonstone happens to be dyed, then that means it's one of those translucent brown or
orange (etc) things. Dyed, maybe, but who cares. It's still only woth pennies per
carat, so it's not that important an issue, and the dyed ones look dyed, not like
something more valuable. The costlier good looking colorless/clear ones with nice blue
or white moonstone flash...-- those aren't treated.

Peter Rowe
(G.G. , 1979)
  #9  
Old January 5th 05, 10:23 AM
vj
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vj found this in rec.crafts.jewelry, from "Peter W.. Rowe,"
:

]So by the time we're done with that, in general, you can probably trust your peridot
and
]moonstones to not be treated in any really signficant way. If there's a little wax to
]help the shine on the moonstones, who cares. Only the really cheap porous ones need
]that, and they don't look like anything much more costly when it's done. . If that
]moonstone happens to be dyed, then that means it's one of those translucent brown or
]orange (etc) things. Dyed, maybe, but who cares. It's still only woth pennies per
]carat, so it's not that important an issue, and the dyed ones look dyed, not like
]something more valuable. The costlier good looking colorless/clear ones with nice blue
]or white moonstone flash...-- those aren't treated.

**smile**
i stand corrected.

but, i DO care if the things i buy have been treated, dyed, waxed, or
whatever. which is why i don't buy randomly any more. because when i
sell it, i want to be able to tell someone EXACTLY what they are
buying. Oran and i have been over it several times. i won't use the
term "cherry quartz", i don't care how accepted it has become, for
instance.

but that's really a different topic!


--
@vicki [SnuggleWench]
(Books) http://www.booksnbytes.com
(Jewelry) http://www.vickijean.com/new.html
(Metalsmithing) http://www.snugglewench.com
yahooID: vjean95967
-----------
"Only Irish coffee provides in a single glass all four essential
food groups: alcohol, caffeine, sugar, and fat." -- Alex Levine
  #10  
Old January 5th 05, 10:28 AM
Peter W.. Rowe,
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On Wed, 05 Jan 2005 01:25:06 -0800, in Xõ vj wrote:

vj found this in rec.crafts.jewelry, from "Peter W.. Rowe,"
:



but, i DO care if the things i buy have been treated, dyed, waxed, or
whatever. which is why i don't buy randomly any more. because when i
sell it, i want to be able to tell someone EXACTLY what they are
buying.


As well you should, in all cases. And in fact, as the law requires. Proper disclosure
is the right policy. Properly, you should be getting this info from the people you buy
the stones from, but sadly, some of them are the worst offenders, especially in the
field of beads, it seems, where there seem to be a higher percentage of sellers who know
how to sell, but don't actually understand the gemology at all.

Oran and i have been over it several times. i won't use the
term "cherry quartz", i don't care how accepted it has become, for
instance.

but that's really a different topic!


Not quite so different a topic.
That one happens to be an excellent example of several problems. The name itself is a
misnomer, one made up by the selling industry with little concern for reality. Not only
is the color due to a treatment, ie crackling the material with thermal shock and then
dying it, but in many or perhaps most cases, the starting material isn't even clear
quartz, but rather, clear glass. About as deceptive as one can get. natural quartz
just never looks quite like that stuff.

Peter
 




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