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Real Ivory or Fake


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#1 Ed Twilbeck

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Posted 29 May 2006 - 02:21 AM

We just got what we think is an Ivory necklace. It is made of 34 strips that are about 2 in long, wide 1/8 thick, and they are carved. What I would like to know how I can tell if it is real ivory or a good fake. The color varies on each piece. Does not feel like any kind of plastic. Any help please. Any simple test that I can do?
Thanks Ed.
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#2 Janel

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Posted 29 May 2006 - 04:05 AM

I am no expert, but would suggest that you look for some indication of grain. Ivory, mammoth and elephant, have a distinct pattern of intersecting arcs when looking at a cross sectioned end. The degree of the angle at the intersection differs between the two sorts of ivory.

Did you really mean 18 (eighteen?) inches thick? That would make for a very heavy necklace. I would not cut into the material before consulting someone experienced in ivory identification could be consulted, unless you purchased the material to be used as raw material for another project. If the pieces are 1/8 (one eighth) inch thick finding the grain might be tricky. Such slender pieces are available as raw material from dealers, and the source may be mammoth in origin. The tusks often delaminate, split and separate from the core material because of the millennia spent in the earth until their discovery, and upon drying out, shrink and split. I'll have a look at my pieces of mammoth tusk that are like that to see if the grain pattern occurs that far out on the tusk.

I suppose that there would be a more scientific way, using specific gravity or would it be specific density, immersion in water, blah blah. Long ago science that I would need reviewing. Then you would need to find out what the real ratio or figure would be for mammoth tusk... Sorry, it is late on a holiday weekend, no more answers for now.

Might a photo help us ID it?
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#3 Guest_DFogg_*

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Posted 29 May 2006 - 11:11 AM

One way of checking is to heat a needle red hot and stick it into the material, you can tell right away whether it is synthetic because it will melt and smell like plastic. There are some celluloid look alikes, but they respond the same way. Real ivory will not melt.

#4 Ed Twilbeck

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Posted 29 May 2006 - 11:14 AM

Thanks Janel. They are 1/8" thick not 18 will change the first post. I can see on some of the edges what looks like grain. I will try to get a picture up later.
Thanks Don I will try that later.
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#5 Janel

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Posted 29 May 2006 - 01:25 PM

Further information about elephant and mammoth ivories by the U.S Fish & Wildlife Services. The article posts images of Schreger lines in elephant and mammoth ivory. This is a handy page to bookmark.

Don's suggestion sounds like a good one, but if you want the piece to retain value, be discrete where you test with the hot needle. Maybe in a drilled cord hole, some out of sight place that would serve your purposes.
Teachers open doors, you enter by yourself. Chinese proverb
What you can do, or dream you can, begin it; Boldness has genius, power and magic in it. ~ Goethe ~


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#6 E George

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Posted 02 May 2007 - 04:40 PM

Hi All,

By now, I'm sure that the issue has been resolved; however, here is another way of detecting "alternative ivory". Ivory at ambient temperature feels "cool" to the touch and "alternative ivory" does not. I learned this from a Scrimshaw artist some years ago.

I tested this after reading this posting. I used an Eskimo walrus tusk carving and a piece of resin ivory. I touched them to the inside of my wrist. That is a temperature sensitive area that mothers used to check the temperature of basby's formula. I could detect a temperature difference. Note: I have never field tested this technic and so have no idea of margin of error for this technic.

I think, if you combined this technic with a visual study of the object for "grain", you might determine the type of material in the field without damaging it.

E George

#7 Phil White

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Posted 03 May 2007 - 12:10 AM

Hi all,

Years ago, when I was in college, studying artifact conservation, I wrote a paper on identification of ivories, bone, and antler for a course in materials technology.

All ivories, as well as bone and antler are all made from the same organic material, (collagen, which binds together a calcium/phosphorous compound) All these materials have some form of growth structure, since they were once livinng material. This structure and color is what distinguishes bone from elephant ivory, from mammoth, from walrus, whale, etc.

Most conservators in a museum environment use a combination of the above techniques, relying strongly on the feel and visual ID part, often using a microscope. As stated, the look, structure, and feel of the material will usually give it away, one way or another.

Artificial ivories were first made in the late 19th century from cellulose nitrate (an explosive compound if processed in a certain way, or allowed to deterriorate), and later with cellulose acetate. Both of these will dissolve in acetone (nail polish remover), and will melt. However, as Janel cautioned, be careful, and avoid doing this on anything valuable.

These materials have a different look about them that will stand out to those who are familiar with them. They have a uniform appearance to the surface, and even when a grain has been added, they still look to perfect and lifeless.

Some people commonly mistake bone or horn for ivory as well. These are easily identified by a slightly open grain, sort of like wood, with a direction and fine pores, which show up especially when stained. Bone will have a few slightly larger pores called "haversian canals" which carried fluids through the bone. These will show up as small specks. No ivories have this grain structure.

Hope this helps,

Phil
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#8 toscano

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Posted 03 May 2007 - 02:58 AM

Phil,
thanks very much for this information.
I find the structure and grain of the natural materials very interesting and understanding it is important for knowing how to approach carving each one.
You wouldn't happen to have a copy of that paper you wrote in college would you? :D

-t

#9 Phil White

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Posted 04 May 2007 - 12:26 AM

Im afraid the paper was written BCE, (before computer era), and I don't have a hard copy any more. All that stuff fell victim to a long overdue purge of old files and such. Of course, once you throw something away you find a use for it shortly thereafter.

Phil
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#10 Mike Ruslander

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Posted 02 July 2007 - 11:55 AM

What Don said above is the surest way to tell. Although it will leave a mark, there is no mistaking that melted plastic smell, when sticking a red hot needle or pin into it. I once bought a really nice looking scrimshawed "whaletooth" at a small country antique store. The item had been marked down in price several times, so I was pretty sure it wasn't real. But it looked nice, (very realistic) and it was a quality piece, and priced to sell. So I bought it, took it home and tried the needle test on the inside. Instant plastic smell. But, as I stated. It looks nice sitting on my cabinet, so I'm happy.



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