How to tell real tortoise from celluloid?

[KnifeSlinger#81]

What does one need to look for to tell real tortoise shell from celluloid tortoise? What was the approximate time real tortoise ceased to be used? I got this shapleigh DE yesterday and I highly doubt it's real tortoise (I'm not that lucky!) but it got me thinking on the subject.

[knife7knut]

There are a couple of ways to differentiate real tortoise shell from celluloid or clear horn stained to look like shell.
I use a 30x loupe(although if your vision is good a 10x should be sufficient)and examine the piece under a bright light. Real tortoise shell is built up in layers much like ivory and under magnification you can discern the the various layers on a curved surface such as the side of a scale.It looks almost like pieces of a jigsaw puzzle.
Clear horn that has been stained can usually be identified by a series of parallel lines along the handle imbedded in the material. Horn is basically keratin(I think that is the name)or hair material that is bound together by a solid material that has hardened much like adhesive. A lot of times on early knives they would put a foil like background under the horn to enhance the colors.
Celluloid can be easily distinguished by what I like to call the "Tongue Test".Simply place the tip of your tongue against the material and it will feel a little like it is burning. Natural material will not do this.
Here are some pictures of two straight razors I own that are real tortoise shell and one that is colored horn.Note that the last picture shows the parallel lines in the handle.

[gsmith7158]

Paul I have one as well that I'm curious about but the test requires a red hot needle to be plunged into the surface . If it smells like hair it's real but if it smells like plastic it's celluloid. I'm not willing to poke a hole in mine!

[philco]

I don't think it's ever necessary to use the hot pin test in order to figure out what the handle material is on any knife. There are other equally effective and less harmful ways of making that determination.

[Railsplitter]

Celluloid can be easily distinguished by what I like to call the "Tongue Test".Simply place the tip of your tongue against the material and it will feel a little like it is burning. Natural material will not do this.

Thank you for that information. I have a knife that I suspect is acrylic but I've been wondering if there's a way to know for sure. It's possible that it could be celluloid but not likely because it's a fairly new knife. I'll give this a try when I get home.

[KnifeSlinger#81]

Celluloid can be easily distinguished by what I like to call the "Tongue Test".Simply place the tip of your tongue against the material and it will feel a little like it is burning. Natural material will not do this.

Well I tried that and it did the trick Does real tortoise have any kind of "grain" to it or does it just look smooth?

[knife7knut]

Celluloid can be easily distinguished by what I like to call the "Tongue Test".Simply place the tip of your tongue against the material and it will feel a little like it is burning. Natural material will not do this.

Well I tried that and it did the trick Does real tortoise have any kind of "grain" to it or does it just look smooth?

If the material has a series of parallel lines(not straight but slightly curved or in a wave) it is probably clear horn that has been stained to simulate tortoise shell. It also has a slightly coarse surface(usually)whereas shell is very glassy smooth.Sometines shell will look like pieces of a jigsaw puzzle due to the layering of the material.Sort of like growth layers in ivory.

[wiseguy]

Hot water , celluloid with smell acrid/caustic when exposed to hot water.... friction, like rubbing briskly with your thumb/finger will make it smell as well

[gsmith7158]

Well I tried the tounge test and got no reaction. So it's either real or I've been eating too much fried coon.

[knife7knut]

Well I tried the tounge test and got no reaction. So it's either real or I've been eating too much fried coon.

I tried magnifying the picture a bit and while I can't see any layering it looks like there may be some lines characteristic of clear horn.If you could get some closeups with light reflecting off the scales I might be able to tell for sure. Whatever the case it is a nice knife.

[gsmith7158]

Here are some pics I took with my new USB microscope at various points along the handle of my knife I believe I can see some layering or scaling.

[kootenay joe]

Greg, those pics are too dark for me to read. Cannot tell what i am looking at ?
kj