Lavender chalcedony change color

A couple years ago, I bought some beads which were listed as
"lavender chalcedony." They are/were kind of a dusty pink color. I
made a pendant with one of these beads, then looked at it a year
later, and the bead had turned blue. I checked the rest of the beads
at that time, and they were blue as well. Some months later, they
turned pink again, and seemed to be staying pink; however, just a
few days ago, I looked at them in the drawer, and one of the beads
was very blue, with others next to it being a little blue. At first I
thought maybe it was a temperature phenomenon, so I tried putting one
bead in the freezer. It did not change. Then I looked on the internet
and saw that some beads respond to UV light with color change. That
got me thinking that maybe it was the newer lightbulbs I had in for
my new lighting system. However, I don’t think that would affect
beads that were stored in a drawer. I have some other stone pendants
in the drawer – maybe one is a particle emitter? If anyone has an
explanation for this color change, I would be very interested to
know.

Thanks,
Jean Petree
Brookline, MA

As far as I know, chalcedony itself should not change color. It
sounds lke the beads were dyed with an unstable dye that is sensitive
to environmental conditions. It seems to be behaving like either a
humidity indicator or litmus paper. Does the humidity vary much
seasonally in Brookline, MA? If you can remember where you bought
them, you could ask the vendor.

I am not an expert, but I could find no reference to “lavender
chalcedony” in half an hour of searching online.

I am not an expert, but I could find no reference to "lavender
chalcedony" in half an hour of searching online. 

You can’t find it because its called “Holly Chalcedony”. Had a
customer today insist that her cheesy $38 pair of earrings were
“pink topaz”. Last week it was some nudnick showing me their “lemon
quartz” that was actually glass. ARGH!

Lisa (Its ffffffreeezing here in So. Cal!) Topanga, CA USA

I have some purple chalcedony cabochons which I purchased at the
Tucson Gem show some years ago The colors of the stones range from a
deep purple to a lighter shade which could be referred to as
lavender. I was told that it comes from Indonesia. The color is very
stable and I have not had any problems with its changing color or
shade.

Alma

How about the surrounding light YOU are standing in. Summer or
Winter Sunlight? Incandescent? Fluorescent Light? That could cause an
apparent color shift.

Judy Shaw

There is a Holley Blue “agate” that is found in Oregon… that may or
may not have been what you have seen. It was hyped pretty hard in
the lapidary trade a few years ago. I bought it, I cut it… and was
not particularly impressed given it was expensive. I still got some
laying around here some where. If you do a web search on holley
blue… you get plenty of hits.

Not sure I’d call it an agate… agates are banded… but Holley
Blue i= s a cryptocrystalline quartz of some variety… that ought
to set off another firestorm on Orchid about what is an
agate/jasper/cryptocrystalline quartz :slight_smile: I did get some stuff out of
Africa years ago from the mine and I totally forget the specific
country… that was an even, but light blue. Unlike Holley Blue…
which is a seam deposit and usually thin and very uneven… this
stuff was chunky and very clean. Lots of lavender stones out
there… very few translucent ones. The only other one that comes to
mind is gel sugilite… very beautiful and very expensive.

Unfortunately, I don’t remember where I bought the beads. Humidity
may be the key as the weather is extremely variable here, but it was
very strange that only one bead in the drawer became very blue, with
adjacent beads becoming less blue as they fanned out:

I hope this link works. After removing the beads from the drawer,
within two days the beads returned to their “normal” pinkish color.

There is beautiful lavender chalcedony from Indonesia that occurs in
thick seams. They have small nodules too.

Some of the deepest lavender chalcedony I’ve seen comes from Turkey
in nodules.

Holley Blue is a lavender agate from Oregon, the closest town to the
mine site is Holley although it’s just a small grocery/gas station,
elementary school and church.

Amethyst Sage agate from Nevada is nodules that have tan jasper
centers and gemmy purple chalcedony rinds, dendrites throughout.

There are also small nodules of lavender chalcedony from Mexico.

These are all natural stones that have, to the best of my knowledge,
stable color.

Have fun !
Markhttp://www.etsy.com/shop/StoneTemple

First ther is lavedner and purple chalcedony besides "Holly Blue"
This material comes from Indonesia and as well from Turkey Theer is
some pruplish blue materiuasl from Kenya where we do mining and as
well from Tanzania. in Afriuca. We have some of this product of
purple chalcedony canochons if interested,

JUst as gem silica chrysocolla, a type of chalcedony colored by
chrysocolla or copper minearls. can have water problems ( just like
opals), chalcedony can also have water problems as well. This means
there can be dihydration of water that leaves the chalcedony (just as
in opal and gem silica chrysocolla) making it loose color and also
tarnsparency or translucency as well. When one puts such back in
water the full color and translucency often can be seen again. There
is a treatment for such. You may contact me off line for such We
also have a new treatment of a silicon sealer ( it is like water )
that will solve the water dihydrationproblems in many opals

Please feel free to contact me offline

Lee Horowitz M.Ed, CAGS,Gemologist
peru blue opal ltd

I suspect your chalcedony is dyed - most of it is. The dye must be
changing as it ages. I have some blue chalcedony that has faded to
almost white as it sat on my display case. Funny thing, none of the
ones inside the case faded, and all were exposed to the same lights.
I expect the ones in the case will fade once they are out in the open
air, as blue is often not a very color fast dye. Perhaps the sulfides
in the air are causing the fading (I have the 3M anti-tarnish strips
inside the case)?

It is odd that the color would change and then go back again to the
original one, but deterioration does funny things sometimes.

Susan
Sun Country Gems LLC
http://www.suncountrygems.com