NOTE: All 5 species of rhino are critically endangered. It is, however, the view of Organic Gems that in order to help protect and save these animals, it is necessary to know what rhino horn is, and how to recognise it. The following is therefore not in any way intended as condoning the poaching of rhinos, but purely to educate.
Black rhino at the Western Plains Zoo, Australia
The horn of the rhinoceros, or rhino as the animal is usually called, grows from the top of the animal’s nose. Other horn-bearing animals (cattle, goats, sheep, etc.), grow their horns on the frontal lobe of the skull, or forehead. Further, rhino horn is the only type of horn that is solid – all the others are horny sheaths covering bony protuberances. (see ‘A Background to Horn’)
Rhino horn, like other types of horn, consists mostly of a protein called keratin, which is fibrous, hard and insoluble, and rich in amino acids. It is very common in the animal kingdom, being the main constituent of hair, nails, claws, feathers, and much more. Its composition varies slightly with each application, thus it is softer and pliable in skin, but hard and durable in hooves. Keratin is waterproof, providing a protective layer, and is also ‘thermoplastic’ which means that not only can its shape can be altered using heat and pressure and the new shape retained after cooling, but the process can be repeated.
Hollow cow horn and ram's horn, and solid rhino horn.
Whereas the horns of cattle and deer are made up of laminated layers of keratin with a fibrous structure, rhino horn is popularly thought to consist entirely of compacted or agglutinated hair. In cross-section it does resemble a tightly packed mass of hair, however true hair grows from follicles, and the tubes of keratin that make up rhino horn grow from the dermal papillae in the skin of the animal, not from follicles.
Left: detail of the base of a rhino horn, showing closely packed tubes of keratin, and right: chipped base of the horn showing the fibrous structure.
In 2006 scientists at Ohio University published their findings following examination of a collection of rhino horns by various processes, including CT scanning. They concluded that the structure of the material most closely resembles the structure of horses’ hooves, and that, as was already known, it is made up of filaments of closely packed keratin embedded in a keratinous matrix. However, they further discovered that the central core of rhino horn is reinforced with calcium and melanin, the former giving added strength, and the latter protecting the keratin from attack by the sun’s UV rays. Melanin is the pigment that gives colour to many things in the animal kingdom, including hair and skin. It is due to this central reinforced core that rhino horns have their characteristic shape. The softer, outer areas are weakened by the sun and worn down through use, resulting in what looks like a horn that is curved and slightly pointed.
THE THREATENED RHINO
Rhino horn has been used for many things over the centuries, from buttons to massive door handles. The most well-known and documented uses are probably the ceremonial dagger handles presented to young boys in the Yemen. The best and most highly valued daggers had rhino horn handles, and the custom helped to decimate the rhino populations. The import of rhino horn was banned by the Yemeni authorities in 1982, so daggers are no longer made with rhino horn handles.
China has always been renowned for its beautiful carvings, and rhino horn was a popular medium, the solid horn material allowing for intricate decoration in deep relief. Indeed rhino horn was so revered in China that its shape was copied in many other materials, such as ceramics or carved jade. Rhino horn carving started in China in about 600 AD. Typical carvings were figures and drinking cups. It was believed that rhino horn cups could detect poison, and indeed it is probable that some alkaloid poisons would react with the chemicals that make up keratin and cause the liquid to bubble. Many of the cups were, however, purely ornamental.
Chinese libation cup, which follows
the shape of the horn.
A commonly held belief is that rhino horn has been used in Chinese medicine as an aphrodisiac. This is not true. The horn has, though, been used in medicines to lower very high fevers, especially in children. Research proved that rhino horn, and one or two other types of horn including buffalo, can lower fevers in laboratory rats, so it is therefore possible that it would work for humans, but it would not be nearly as effective as a modern medicine such as paracetamol. Another more recent belief was that it could cure cancer, but this has been totally disproved by scientific tests.
Several hundred years ago rhinos wandered over much of our planet. Even in the 1970s there were estimated to be 20,000 rhino in Kenya alone. Ten years later there were less than 400. It is estimated that between 1970 and 1992 96% of the world’s population of rhinos was killed by poachers. This was due partly to loss of habitat, but mostly to our love of rhino horn. The horns grow throughout the life of the animal, and if damaged or lost can re-grow.
The rhino was added to CITES* Appendix I in 1977, and all international trade in rhino horn, and indeed in any part of a rhino, is banned under the agreement by all the CITES signatories. Sadly this has not prevented the further decimation of the various rhino species by poaching for supply to the black market, though in some areas the measures put into place by conservation groups have enabled the rhino populations to begin to recover. In some instances the reward for informing the authorities about poaching is higher than the reward given to the poacher for the animal’s horn. But it is unlikely that rhino populations will ever again be of substantial size, and the magnificent animals remain greatly endangered.
There are five species of rhino left today. Of these, the two African species are the best known: The African white rhino is the second largest land animal in the world (the largest being the elephant). It carries 2 horns on its nose, the largest in the front. The African black rhino is slightly smaller, and also carries two horns, the largest in the front. The shape of the two species’ horns is slightly different, the black having an almost circular cross-section at the base, while the horn of the white is slightly horseshoe shaped. In spite of their names, the animals are the same colour.
The three Asian rhinos are slightly different. The horns of the Asian rhinos tend to be slimmer and more spread at the base, while the African rhinos’ horns end more abruptly, with less of a ‘skirt’. The male Javan rhinos carry one horn only, while the females usually have none. There are thought to be almost no Javan rhinos left in the wild today, though a few can be seen in zoos. The Sumatran rhino is also very critically endangered. It is similar to the other Asian rhinos but carries two small horns. The Indian rhino is slightly larger than the Javan, and looks as though it is armour plated as its skin hangs in folds around its limbs. The skin is very thick but – contrary to olden belief -- it is neither bullet nor arrow proof.
CARVING, TREATMENTS and COPIES
As already stated, rhino horn can be carved, and when polished it displays a satin lustre. In some cases it has been inlaid with mother-of-pearl, ivory, and other materials. Less well known is the fact that it has also been stained, and it is not unknown for artefacts made from rhino horn to be coated with some form of lacquer which gives a shiny surface without the need for delicate polishing.
Being solid for its entire length, rhino horn is unique. However small items made from buffalo horn (which is solid at its tip and is the material most used for imitating rhino horn), may be confused with ‘the real thing’, as the two materials can be difficult to distinguish.
Left: rhino horn which is round and buffalo horn
which is a flattened triangular shape.
Right: section of buffalo horn showing its shape and
In a larger carving the shape of the finished item can be an indication of its origin, as can whether or not it is hollow. Large, intricate carvings have been made from whole buffalo horns, but the horns are not round – near the base they become rather flat. Further, the horn is hollow for most of its length and is not thick enough to be carved in high relief.
Buffalo horn is made up of layers of fibrous keratin, while rhino horn looks like compressed hair. These differences should be apparent on careful inspection. Another distinguishing factor is that in worn areas, rhino horn may look ‘frayed’ due to the hair-like structure, while buffalo horn tends to ‘flake’ due to its laminated structure.
If horn is reshaped using heat and pressure it may lose some of the fibrous appearance. Rhino horn has generally been regarded as too precious to treat in this way, so the structure remains visible. Buffalo horn can be stained to resemble rhino horn, which occurs naturally in a variety of browns, from pale through rich to quite dark brown.
© 2018 Maggie Campbell Pedersen All rights reserved.