Is this bone or ivory ? Listed as bone set...

Seller lists it as a bone set. @greghunt ?

Sellers have an incentive to lie in many places these days, but sadly I am no expert on telling bone and ivory apart.  I just have an interest in the CITES process. 

The yellowing and cracking suggests some age and that the pieces are made of some material like ivory.  Here is a CITES document on identification, none of it can be done from a photo.  https://cites.org/sites/default/files/eng/resources/pub/E-Ivory-guide.pdf and here is something less technical https://www.realorrepro.com/article/Ivory-genuine-fake--confusing 

I wonder at the knights all cracking but the rooks (also quite thick) not.  The patina is uneven: compare the two bishops, on the left-hand bishop there is no yellowing where the fingers would touch it, and on the right it is quite yellowed, you might ask if they have been cleaned.  The two rooks, which have carving all over them and which might be harder to clean, are more consistently yellowed.  Keep in mind, I am no expert, just habitually paranoid.  

Sorry I can't really help with your question.  

The thing that stands out for me is that all of the pieces have similar looking bases except for the rooks. In fact all of the pieces look like a normal Staunton pattern set - except the rooks.

I'm no expert in bone/ivory sets either though.

How big are these pieces? I have a bone set, and in my set each piece is composed of 2 or 3 pieces of bone screwed together - I understand that the reason for this is that large pieces of (bovine) bone were difficult to get.

Can't help I'm afraid. In the UK antique ivory is still legal, but I've never really wanted an ivory set - since I like the look of wood.

I did a quick google and found that elephant ivory is sometimes passed off as bone, but I expect you've already discovered that for yourself!

It does look to be a high quality set though

@ipswichmatt @greghunt Are ivory pieces screwed in like bone?

I'm not aware of ivory pieces being made screwed together like that - there's no reason to think they're not bone IMO.

But then again, until you posted these, I was unaware that elephant bone was used for chess sets at all!

This reminds me of an episode of "Pawn Stars" where a woman tries to sell her elephant/mammoth tusk and Rick points out that it's a piece of wood with joined-up panels of bone placed over the wood. These were commonly sold to tourists, passing bone off as ivory. Now it seems, things are reversed and people are trying to pass ivory off as bone

I believe that they were usually turned from a single piece (except perhaps for the knights). 

I wouldn't say it couldn't be elephant, but you have to wonder whether this is an example of the vendor pretending to pretend that they're ivory.  Imagine getting the elephant bone to Europe for manufacture - you cut the tusks off (the most valuable bit) very quickly and then spend ages de-fleshing the bones that are not worth near so much per kilo in order to ship them.  Much easier to use locally sourced bone in Europe.  It makes me doubt that elephant bone was ever used.  Here is an interesting article by Alan Dewey on the subject (that doesn't mention elephant bone): http://www.chessspy.com/articles/Bone%20and%20Darlow.pdf 

Lots of stuff was made from bone before the invention of plastics.

This is a 19th century set made in Canton, which is definitely ivory and I think there is a good chance that it is mammoth ivory, not elephant. I have several of these sets made of fossil ivory, actually.

Also, it is not unusual for ivory sets to be made of several parts screwed together. The Canton ivory sets were usually made this way. There are also monobloc sets, but they are less common, at least in this particular type.

Bone and ivory are absolutely different from each other, even more so in elephants, I dare say. Ivory is mainly made of dentin tissue, as are all teeth. Unlike ivory, the main component of bone tissue is not dentin but collagen. Certain parts of bone tissue are also well suited for mechanical processing. Nevertheless, bone has a decisive disadvantage compared to ivory. Whereas the tusk of an elephant, for example, has massive layers of dentin that also allow for the making of larger workpieces, the material that can be processed in bone is usually very limited, at least in the case of the common types of bone that were used extensively for the manufacture of chess pieces.

As for the question whether this is elephant bone - no, it is not. The interior of the bone consists of osteons, a system of lamellae running in the longitudinal direction of the bone, which are arranged concentrically around small canals and form the so-called Havers system. This is what you can see on the pictures above, the small dark dots and lines on the material, which help to distinguish bone tissue from ivory. These canals are small in bones of small animals, but they are larger in bones of larger animals. This is also the reason, why elephant bone is not really the material to look for when making chess pieces. The canals in the bone would be rather large, I suppose, and it would be difficult to impossible to reach a smooth polished surface without larger dots and lines.

Here is a picture of a bone piece, in which you can clearly see the canals of the Haversian system.

And here is a rook made of bone as opposed to a rook made of ivory.

Thanks @EfimLG47. The ivory rook looks very clean compared to the bone one. I am unfamiliar with ivory as am I unable to own and handle one. I do have a bone set and it has those dots and lines that you described.

On bone sets, do they crack as often as wood sets? Would you recommend oiling them with mineral oil? I have a bone set and am unsure if it should just be left alone. I have read about oiling bone knife handles.

I have not experienced cracking of bone pieces yet and have so far not applied oil. I am not sure if it really helps in the same way as it helps for wooden pieces. Personally, I would be afraid that it might give a yellowish stain to the pieces, so I rather keep the bone at normal humidity and temperature levels without any further treatment. The only thing I did in the past in order to "whiten" them was to bleach them overnight in 12% H2O2 solution, which really made a difference. Here is a bone knight which about two weeks ago I treated in this way, picture 1 before, picture 2 after.

@EfimLG47 The knight looks brand new now. Was there too much dirt or discoloration on the rest of the white pieces?

I'm surprised that the ivory industry in Canton then would have used something so difficult to get as mammoth ivory when elephant ivory was fairly easy to obtain in quantity and not obviously different.  Were they advertised as such?  

@greghunt @EfimLG47 Would mammoth ivory have cost more than elephant ivory back in the 19th century?

Retrieving a mammoth tusk looks like a lot more work than simply shooting down an African elephant.  Were mammoth tusks much easier to find back then?

https://www.boredpanda.com/mammoth-tusk-hunting-russia/

I would have thought that they would be harder to find, but I don't have hard data for that.  I'll wait for Efim to comment.  

The pieces were dusty, but even after I cleaned them they retained an unattractive yellowish tone, which is why I decided to bleach them.

I am actually not aware of that and was wondering myself, why mammoth ivory was used in 19the century Canton carvings. Ivory carving has a long tradition in China which goes back to the times, when elephants still had their habitat in China. Once the Chinese elephants had disappeared, the ivory was sourced from Africa via trade routes between Zanzibar and China. Therefore I have no idea why fossil ivory was used, but the fact is that I have seen (and actually own myself) several Canton ivory sets, which according to an expert I have asked were made of mammoth ivory. Here is a picture of the underside of one piece from such set, showing the narrow Schreger angle typical for mammoth ivory. According to the expert I asked (myself definitely not being one), this Schreger angle together with the visible nerve and the little yellowish part are indicating that this is most likely mammoth ivory (the yellowish part apparently being a water stain retained by moisture from the tusk lying in the ground over a longer period of time).

By the way, two more comments on the pictures of the first set:

To me this actually looks like a mixed set. The rooks look as if they are from a different set. Rooks in Canton ivory sets usually look different.

And also the finials on the queens do not look authentic to me. It seems as if they were taken from a different set.