Back to Ganoksin | FAQ | Contact

Synthetic onyx


#1

Hello All

Much to my disgust there seems to be an ever increasing number of
synthetic gems to be watchful of when buying. Even the cheap ones
that you’d never expect anyone would go to the trouble to create
such a material. Onyx is the latest one for me to be worried about. I
guess it’s being made for kitchen & bathroom bench tops & vanities.
Anyway, does anyone know the specifics on this & how can we test for
it ?

Thanks
Phil


#2

Magnification, scratch, feel. Are they mounted or loose? Are you
meaning look alike not created onyx. I am not aware of synthetic
onyx but look alike agates. Loose is a bit easier to detect. If the
counter top type is granite top that might be a little harder. Too
would be what color of onyx, black is not worth cutting synthetics
and some of the simulations of onyx are polymer filled in silver
jewelry.


#3

Phil- I don’t use onyx. When I need big black I always go with black
jade. Onyx can be very brittle and subject to chipping. Black Jade is
really tough and much more stable.

Have fun and make lots of jewelry.
Jo Haemer
www.timothywgreen.com


#4

We have always had to deal with synthetics, misnomers, treated stuff.
We all draw the line differently. Some Facetors cut cz and synthetic
ruby/sapphire. Heck, 99% of the black onyx out there is dyed
chalcedony. And most “Onyx” is calcite. Go figure. Anything called
green amethyst is heat treated amethyst but should be called
"prasiolite" because that’s what green quartz is called. We could go
in about crackle chalcedony “fire agate” or red glass filled ruby or
what have you. Red Andesine?

The Gem Industry is full of a lot of garbage, hate to say…

TL Goodwin
Lapidary/Metalsmith
http://thepacifikimage.com


#5

most of what I see is treated agate mined from Brazil or Uruguay.
Turn dull grey into lovely stripey black/white. Been done for a
couple of centuries in Idar.

Nick Royall


#6

We have always had to deal with synthetics, misnomers, treated stuff.
We all draw the line differently. Some Facetors cut cz and synthetic
ruby/sapphire. Heck, 99% of the black onyx out there is dyed
chalcedony. And most “Onyx” is calcite. Go figure. Anything called
green amethyst is heat treated amethyst but should be called
"prasiolite" because that’s what green quartz is called. We could go
in about crackle chalcedony “fire agate” or red glass filled ruby or
what have you. Red Andesine?

The Gem Industry is full of a lot of garbage, hate to say…

TL Goodwin
Lapidary/Metalsmith
http://thepacifikimage.com


#7

Hi Phil,

First, the term “onyx” has been misused. The material in question is
dyed quartzite and always has been. Onyx is a mineralogical term for
a form of calcite, which would be totally unusable for what we use
"black onyx" for.

Having said that, the best current source for black onyx is probably
just buying larger pieces from a reliable source and re-cutting as
needed. Plenty is available from the usual suppliers. I’ve seen black
tourmaline (schorl) used as well as black nephrite jade, but I don’t
think anyone usually cares as long as the material is black.
Personally, I’d welcome a durable, evenly-colored substitute. (Not
synthetic, that’s misusing another term!!!)

Wayne Emery
thelittlecameras.com