Glass or Black Onyx?

Jewelry Discussion
1

I have inherited a necklace of black faceted graduated beads from my
late mother-in-law. Her jewellery range from the sublimely expensive
to plastic, and I can’t tell what these beads are made of. They may
be glass, onyx or something else. Is there an easy test I can do to
determine whether they are glass?

Thank you
Pat

2

Hold them up to a strong light. If they are glass the edges of the
facets will appear translucent. If this is not the case then the
necklace would almost certainly be jet and probably made in Whitby.

Bill Bedford

3

Hello, Pat -

Any trusted jewelers in your area? Also - can you determine their
age? That can help with identifying vintage or antique jewelry
components and materials. They may be jet - which is a type of black
glass - often used for “mourning beads”, worn after the death of a
loved one. Do you have a photo? The description sounds like they may
be glass mourning beads, depending on the age.

I’ve learned to tell the difference by close examination - tiny
chips do appear on many of them under magnification - which look
different in glass than in Onyx. But I’m not a jeweler nor gemologist

  • just a hunch. Been working with vintage jewelry for some time -
    and have seen tons of jet in the type of necklace you describe

Best to you,
Mary Beth

4

Pat,

Hold the bead to your lips, if it feels warm it’s probably glass. But
testing in a refractometer is usually a better method.

Alain.

5

True jet is hard coal, which would be much softer than onyx (softer
than true onyx, which is a chalcedony; much travertine [calcite] is
also sold as “onyx”).

Tas

6 
    They may be jet - which is a type of black glass -

Sorry Jet is not glass – It is mineralised wood, bit like a very
hard coal. See the Whitby Jet Museum site for more

http://www.durain.demon.co.uk/jet

Bill Bedford

7 
They may be jet - which is a type of black glass - often used for
"mourning beads", worn after the death of a loved one.

Jet was used for mourning jewelry, but it is a form of coal, not
glass.

Lee Einer
Dos Manos Jewelry
http://www.dosmanosjewelry.com

8

Sorry, but I couldn’t let that go by. There is too much
mis’out there.’ Jet is NOT glass. It is similar to coal.

David Barzilay
Lord of the Rings
607 S Hill St Ste 850
Los Angeles, CA 90014-1718
213-488-9157

9

One of the many things I love about Orchidians, If ya mess up, they
will set ya straight. Jet is not glass, I stand corrected.

I’m going to the Whitby Jet Museum site site to read right now! :o)

Gratefully,
Mary Beth

10 
    One of the many things I love about Orchidians, If ya mess up,
they will set ya straight. Jet is not glass, I stand corrected.
I'm going to the Whitby Jet Museum site site to read right now!
:o)

Better yet Mary Beth - go to Whitby itself, its one of my most
favourite places in the UK along with the other small fishing
villages nearby - Staithes, Robin Hood’s Bay, Runswick Bay etc…
What’s more, they are less than 100 miles from my door…

Best Wishes,

Ian
Ian W. Wright
Sheffield UK

11 
 Sorry, but I couldn't let that go by. There is too much
mis'out there.' Jet is NOT glass. It is similar to
coal.

Maybe part of the confusion is on account of obsidian, which is
black volcanic glass (I believe).

Most of the black stuff I have come across seems to be dyed agate.

Noel

12

Hi Ian -

Better yet Mary Beth - go to Whitby itself, its one of my most
favourite places in the UK along with the other small fishing
villages nearby - Staithes, Robin Hood's Bay, Runswick Bay etc..
What's more, they are less than 100 miles from my door..

That sounds wonderful, if I am ever in the UK, I will definitely
go!! I cannot think of a better excuse to visit. :o)

Also - in reply to a few people who emailed me off-list - You are
right, I spent decades dealing in Vintage jewelry, and was buying a
lot of glass beads from a dealer-friend in the UK. She sells a lot of
what she calls “French Jet”, which was one place I got sidetracked
from the facts.

I understand is some sort of glass. (Like French Ivory is a
plastic). More of the same advice we often share here follows - about
researching all the tricky names by which gems, metals and items are
called. “Nickel silver” was one I learned about here on Orchid. I
have run across it often - mostly in men’s vintage ID bracelets. But
I was never sure exactly what it was until I came here.

Thank you to those of you kindly pointed out the error, and gave me
some new facts to ponder. I love how you always learn something new
here!

Best to All,
Mary Beth In NH

where the many birds are having a mad “tweet-fest” every morning at
dawn. If the development slows down a little, maybe my pals the
salamanders will return. Still finding tree frogs in the garage after
a rainstorm…