About Ivory and Bone Over the coming weeks I will be adding information about Ivory and Bone to this section of the site. This will include information on the use of the material for jewellery and advice on how to tell the difference between the different materials. Legal Trade In order to protect the world's most endangered species of animals and plants the trade in certain animal and plant products is regulated or banned. A worldwide ban on commercial imports of raw and worked ivory came into force in 1989-1990 through the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The EU currently allows the import of ivory antiques defined as items manufactured prior to 1 June 1947. The Convention also allows the free trade of antique items that are already within the EU. All of the item sold on this website comply with the convention and we fully support the ongoing protection of endangered species and wild fauna and flora. Where Does Ivory Come From? People tend to associate Ivory with elephant tusks but this is only one source of the material used in jewellery manufacture. Ivory comes from a variety of sources that include: Elephants This category includes ivory from both Indian and African elephants, as well as ivory from mammoths and mastodon. The tusks, or upper incisors, of these animals are used and they can have a cross section of up to 20cm (8"), and be up to 2.5m (almost 3 yards) long. They are oval in cross section, and are made up of a hard, dense tissue called dentin, which is 70% inorganic material, and 30% collagen. Unlike human teeth, elephant tusks do not have an enamel coating. They do however have a cementum layer, which ivory dealers refer to as the "bark" or the "rind". Occasionally this layer is retained on a piece of worked ivory. One-third to one-half of an elephant tusk is hollow. Hippopotamus This is the second most commonly used ivory, after elephant ivory. Often used for flat items, such as buttons and inlays, it comes from the lower canines and incisors of hippos. The size varies, depending on the size of the animal. The lower canine is curved and has a triangular cross section; the incisor is straighter and has a circular cross section. Both have two layers of dentin: an outer, primary dentin, and an inner, secondary dentin. The innermost layer has a marbled appearance, which differs by species, and can even appear to have a greenish cast. Unlike elephant ivory, hippo ivory has a thick enamel coating and also a finer grain structure. Hippo ivory is denser than elephant ivory and therefore harder to carve. Walrus This ivory comes from the upper canines of walrus. It is oval in cross section and can be over 2 feet in length. It has an inner dentin layer, which forms as the tusk grows, and leaves a marbled look on finished objects. Walrus ivory is used primarily for small objects. Sperm Whale Thirty teeth of the sperm whale can be used for ivory. Each of these teeth can be up to 8" long and 3" across and they are hollow for the first half of their length. Sperm whale ivory is easily confused with walrus ivory, as both have two distinct layers. The inner layer of sperm whale ivory is however much larger. In a longitudinal section sperm whale dentin has yellow "globules" included in the marbilization. Hornbill This comes from the casque or epithema of the Helmeted Hornbill, a bird native to the East Indies. It is distinguished from the rest of its family (the Bucerotidae) by having the front of its almost vertical and slightly convex epithema made of a solid mass of horn. This "horn" or "ivory" is quite hard and closely textured. This substance is used to make small objects such as buckles and brooches, and is highly valued by the Chinese. In cross section, you can see a bright yellow interior with a scarlet rim. Imitation Ivory Vegetable Ivory The source of vegetable ivory is the inner seed of the South American ivory palm, and is thus completely made of cellulose (rather than collagen). These seeds are the size and shape of a small hen's egg. They are very hard, and are solid all the way through. Vegetable ivory is smooth, takes a good polish, easily absorbs dyes, and is relatively inexpensive. It is used for small items, such as dice and buttons. Since the second world war vegetable ivory has been largely replaced by plastics. Synthetic Ivory Celluloid has been used as an excellent ivory substitute since it was first invented by Alexander Parkes in 1865. Casein, a calcium salt and protein has also been used as a synthetic form of ivory. Names for these "faux ivories" include French Ivory, Ivoride, Genuine French Ivory and Ivorine. These synthetics can be produced with similar grain patterns as real ivory. But in general the patterns are very regular in the fakes and more irregular in the real thing. In instances of very good imitations (i.e. using celluloid), chemical and other tests are required to tell real ivory and the fakes apart. Plastic Modern ivory imitations are now generally made using a variety of plastic materials. In many cases these are easily identifiable through features created during the moulding process such as lines where the two halves of the mould join. However some better imitations can only be identified by chemical tests or the use of a hot pin.