Hi all–It never occurred to me to wonder what Goldstone is
until someone told me it is really glass with little flecks of
metal in it, and can be made in any color. I always thought it
was a mineral of some kind–or a semiprecious stone.
Anyone know what is it actually made of? Sandra
Hi all–It never occurred to me to wonder what Goldstone is
Goldstone is glass containing minute particles of copper. It was
originally manufactured by Italian monks.
Ron @ Mills Gem, Los Osos, CA.
The “someone” is right – it is of glass, man-made. (Originated
by Monks in Italy, I have been told). Beautiful stuff! Margaret
I do not know the formula…Originally it was made by one of the
order of catholic monks in Italy. I believe it was used in
mosaic tile first… It is a man made stone… don Vercellotti
Goldstone is exactly what you were told: basically glass with
different specks in it. The story goes that it was originally made
only in one monastery (in Italy?), and that for centuries the
monks kept the recipe a secret to avoid any competition.
It’s now made in a variety of colors.
sandra - goldstone is indeed made of glass: italian glass workers
put in flecks of copper at the molten stage & it is poured into
’flats’, cut up into slabs & distributed to the trade. it is the
only man-made stone to be included in almost all
gemstone/lapidary sources. it’s made in the more ubiquitous
light brown, midnight blue & a slightly pinkish hue, an almost
olive green (found in some vintage jewelry). it is cut, ground &
polished using the same methods as working with obsidian
(volcanic glass). the material is very stable, holds a high
polish & has a durability that surpasses a lot of natural
’rocks’ or right now i have about a 2 kilo slab of it
in with my half of a ton of other rocks. hope this helped - ive
Here are 2 URLs for where Arrow Springs lists its goldstone and
then one URL for Franz Bead’s goldstone page. These are not the
only suppliers by any means but I have ordered from both and they
have treated me fairly. You may have to cut and paste the URLs if
line editor puts in a carriage return in the middle.
Note they come in two forms, the rods and the chips/pieces.
Although small sized rods and little chips are fairly safe the
bigger pieces and also the larger diameter rods tend to explode
when heated. The chips and pieces have to be coated with clear
glass and drawn out to make stringers anyway. If the end of a rod
explodes it often just braks off the tip but the pieces explode
in all directions. I usually use a 5-6mm rod and have some
7-8mm rod I use sometimes but dislike the pieces as I don’t like
picking out shards of glass from my hands. Note also they are
not real adventurine but are synthetic.
--It never occurred to me to wonder what Goldstone is until someone told me it is really glass with little flecks of metal in it, and can be made in any color. I always thought it was a mineral of some kind--or a semiprecious stone. Anyone know what is it actually made of?
It’a manmade glass, with copper crystals in it. I believe, but
don’t actually know for sure, that the copper is added to the
glass as a salt, and then the glass subjected to reducing
conditions or otherwise handled so the salt reduces to copper,
which would then form crystals precipitating from solution in
the melt. Thus their nice perfect little flake form. That part
is just a guess, though. The story goes that this stuff was
first made by a specific order of monks in italy near the big
italian glass blowing centers that have been active in that
activity since the middle ages or thereabouts. They kept it
secret for a long time, and for a long time it was available only
in it’s brown/copper color. This is how it acquired it’s
occasional significance as a religious item, or in religeous
jewelry. Whether it’s now made only by those monks is something I
don’t know, but I seriously doubt it. Hope this helps, Peter
... it is cut, ground & polished using the same methods as working with obsidian (volcanic glass). the material is very stable, holds a high polish & has a durability that surpasses a lot of natural 'rocks' or ... hope this helped - ive
Ive, Since it is a glass, I’ll not argue with it’s stability as
you state. but durability? Not so much. Glass may be pretty
stable to things like moderately elevated temperatures,
ultraviolet, color change, or all that sort of stuff that plagues
some stones, especially some irradiated/treated ones. But it’s
not especially hard or tough. As gems go, this is a bit soft,
(softer than the quartz gems, only a bit harder than opal) and
like all normal glass, it’s a bit brittle and easy to chip/break
if you’re not careful. Yes, it’s more durable than things like
malachite, turqoise, pearl, opal or amber. But the majority of
fine gem materials, including all the quartz family (from
amethyst and citrine to all the agates, jaspers, chalcedonies of
all sorts) beryls, topaz, tourmaline, corundum, diamond, jade,
etc, are all harder and generally more durable.
Peter Rowe G.G.
Those overly long Arrow Springs URLs did break in transit. If
one goes to http://www.innercite.com/~flameon/ then from there
links to ‘catalog’ then on to ‘tools and supplies’ then on to
‘supplies’ then about halfway down the ‘supplies’ page they come
to the goldstone pieces. I wonder if lapidarists could cut and
polish the chunks like they do rocks? I know the chunks are 'way
too big for glass bead making. Geo
Peter, In your response to Ive, I noticed a reference to
There has been a discussion on the two Faceter lists I read,
with reference to quartz for an example being far more difficult
to polish than remembered. The suggestion being that irradiation/
treatment has changed the known characteristic of the stone.
If I read you right, the heat generated while polishing may be
behind the problem?
Perhaps some of the Jewelers online who are also Faceters can add
to this wondering out loud of mine. May I then have permission to
port the replies (if any) over?
Dear Terry: It has been my experience that natural quartz that
has been highly irradiated (probably Cobalt 60) to be more prone
to cracking and chipping during faceting. I didn’t notice
differences in polishing with the oro verde (green-gold, neon)
material. Ed Katz, G.G @Ed_Katz
I have a friend who makes flame worked glass beads. Sometimes
she uses a touch of goldstone in a bead design. She melts a
broken piece of goldstone and stretches it into a stringer or
includes it with other glass colors in making canes.