Hi everyone!!! Just an add to fading stones. It has been an experience
of mine that Apricot Topaz fades very quickly when exposed to direct
sun light. We did a couple of show out of doors on really sunny days
only to discover that a couple of my nice Apricot pieces were quite a
bit lighter then when we started. Feel that it is important to get all
the that one can so they can pass it on to perspective
buyers. ( some natural stones do fade ) John here in
Greenfield. Mass. " Everyone have a great day "
Yes, and the sherry-colored Topaz from Utah (Topaz Mountain) also
fades in sunlight. margaret
Yes, and the sherry-colored Topaz from Utah (Topaz Mountain) also
fades in sunlight. margaret
Does this apply to Imperial Topaz as well? I have one set into a
ring, and wondered if I should be cautious about exposure to sunlight.
Thanks!
Judith Marsh
Hi All, Regarding the sherry colored Topaz from Utah. I was told by
the operator of the local Rock Shop that Yes they will fade if not
radiated. But the funny thing was that all you had to do was to hold
them up to a flourescent light for about 30 minutes and that was
enough radiation to make the Topaz stable! Haven’t tried it out yet,
But I’m gullible and it might work. However the light from an F40cw
flourescent lamp will bleach just about anything! Maybe she forgot to
tell me the color of the lamp to try!
I have heard of radiating them, but have heard that it is only a
temporary restoration. I haven’t heard of the fluorescent lamp bit ,
and thus have not tried it either. But it sounds unlikely to me; I
cannot really believe that you get enough radiation from a
fluorescent. And, if you do get enough radiation from the fluorescent,
then why does it fade in the sun in the first place? Surely there is
at least that much (collective) radiation in the sun’s rays
(especially in that hot desert sun), that it should not have faded in
the first place. ???
Anybody else?
Margaret
@Margaret_Malm
Huh? someone is very confused here. Holding a stone, any light
sensative stone, up to ANY light source, will never make it stable
against future fading from sunlight, unless of course we mean that the
initial holding it up to the light is enough to fade it as far as it
would ever fade anyway. Then, of course, it’s stable all right…
I’ve never heard of any stone where irradiating the thing makes it
stable against fading in the light. Usually, the ones that fade are
the ones that have been irradiated, and the color change induced is
not stable. Some natural colors also fade too, but irradiating the
stones doesn’t protect whatever color is already there from future
fading… When we irradiate stones to change the color, the most
common cause of the color change is that the irradiation bumps one or
more electrons from it’s current stable orbit to a higher energy, but
stable enough one. This change can change colors. When entropy
exerts itself, and the electron drops back to it’s original orbit
(which is almost always the most stable state), then the color change
reverts, or fades. Sometimes the higher electron orbit happens to
also be quite stable, and it takes a good deal of external energy
input to get it to jump back down. These stones may be stable enough
that sunlight does not have enough energy to cause this reversion.
Other times, even the slightest energy input is enought to allow the
electron to get back to it’s original state. Those stones will fade
quickly.
With topaz, it’s a bit more complex, since often stones are both
irradiated, and then heat treated. The irradiation causes several
changes, some more stable than others. After irradiation, the stones
are carefully heat treated, which anneals (fades the color) certain of
the irradiation caused changes, while not being able to affect the
others. Additionally, the heat treatment can sometimes also cause
actual changes in things like the oxidation state of various ions in
the stone, thus actually amounting to chemical changes. The initial
color after irradiation is oten not stable. After heat treatment,
what’s left IS usually stable. But the original color after
irradiation is often a lot darker too, so sometimes stones forgo the
second heat treat. Perhaps this need to heat treat the stones after
irradiation is what your dealer was actually intending to convey.
Peter Rowe
Margaret, Mark Lucini’s answer sounds the most logical to me (heat
actually for however long that the stone lays out in it). Exposed
Topaz bleaches quickly in the Sun and the Sun gets very hot thereby
providing two things that when added together probably take the color
out of the stone as quickly as anything! Isn’t Nature wonderful!
Supposedly, the radiation of the flourescent light made the Topaz
stable. Like I said, this is second party and I can’t
vouch for it as I haven’t tried it.
Margaret, Pink and apricot topaz is often colored through a process
of electron bombardment to get these colors. This takes special
equipment and can not be done at home.
Etienne Perret
Designing Colored Diamond Jewels
< www.etienneperret.com >
20 Main St
Camden, Maine
USA 04843
tel.+207.236.9696
fax.+207.236.9698