What is the history of these materials in knife handles?

The history is rich. From the first time prehistoric man laced a bone handle to a piece of flint, he realized the importance in this handle material. Bones, tusks, and antlers from living animals memorialized the hunt, perhaps personalized and anointed his knife with the spoils of his hunting efforts. There are good examples of carving ivory from as early as ancient Babylonia, 2300 B.C. The tradition of using animal parts for his handles continued throughout history, and continues today.

What are the advantages of using these materials on knife handles? Tradition, beauty, texture, and value.

Usually, the choice to use horn, bone, or ivory is one of tradition. Most of us grew up carrying jigged bone handled pocket knives, and in my day, we even carried our knives to school. Every boy had his own knife, and occasionally we would find one that had been dropped, or lost, laying in the dirt around the playground equipment. We would often play what we called "chicken," where we would throw the knife between the feet of our opponent in turns, and move our feet to the landing point of the blade, ever closer, until either one of our feet got stuck with the point of the knife, or we "chickened" out. Usually, our knives were so dull, they wouldn't penetrate a canvas tennis shoe-  boy, things have changed today! Also, most of us are familiar with a stag handled hunting knife. This is the knife style our fathers and our grandfathers grew up with. You didn't take a wooden handled butcher's knife on a hunt, you took a stag handled knife. Again, this probably hearkens back to prehistoric principles of the hunt.

The choice to use horn, bone, shell, or ivory is also one of beauty. Nothing looks like a piece of stag, furrowed and rough. Fresh elephant ivory is a beautiful solid creamy color, suitable for engraving, carving, or scrimshaw. Mammoth ivory can have stunning patterns in rich browns, reds, and even blues. The shapes of many antlers and horns left "in the round" lend themselves to handles, the forms compliment knives and sometimes modern stands and fittings. Shells can have stunning iridescent light play and a smooth lustrous finish.

The texture of many of these materials helps improve grip strength. Many horns, bones, and ivories become "sticky" when wet, thus improving grip security when working. The texture adds visual interest and contrast to a smooth and polished blade. The texture of a fine organic material makes a transition between the cold, inorganic steel blade to the living, warm, moving hand. The polished texture of ivory has a smooth comfortable feel, jigged bone is attractive and secure in the hand.

Value is one of the more modern reasons to use this material. Ivories are hard to come by, ancient ivories are a limited resource. Mammoth and mastodon ivory, fossil walrus tusk, and fossil oosic are some of the most valuable and sought after knife handle materials. Some shells, coral, and pearl families are rare and expensive. Many of these materials increase the value of the knife dramatically.

What are the limitations or disadvantages of using these materials on modern knives?

The first problem with them is that all the materials listed on this page are somewhat porous, and this effects stability. There are lesser and greater degrees of porosity, and that helps with good choices for handle applications. Being porous and organic, these materials absorb moisture, loose moisture, absorb contaminants, salts, and soil. Extra care must be taken to keep the handle material clean and dry. Sudden changes in relative humidity (like moving from a damp forested environment to a dry air conditioned room) can cause such a variation in moisture content that the material shrinks and cracks away from bolsters, guards, or pins within hours.

Temperature also affects these materials radically. Putting a bone or ivory handled knife in the direct sun or under a bright display lamp for a couple hours can ruin it. Part of the problem is moisture content, but another factor is the coefficient of thermal expansion. Since the coefficient is much different than steel, movement can be outright extreme. Often, pins and epoxy do not prevent movement, and eventually the bone, horn, or ivory shrinks, checks, and cracks away from the pins, bolsters and tang. This does not necessarily mean the end of the knife. As long as the knife is kept reasonably dry, it should last in service.

Light can be another enemy. Many of these organic materials react to the long term exposure of light, sometimes bleaching and becoming flat in color and depth. Since they are usually laying on one side, the other side will not bleach, and then the knife looks like a different handle material was put on each side. On a hidden tang knife it can look as if it's been laying in the desert for a century. And the intensity of the light also adds to the effects of drying detailed above.

Sometimes, checking in ivory is an advantage. It testifies to the age of the knife handle, and elephant ivory is graceful and forgiving in its yellowing and checking. It's proof that it is indeed ivory, because replacements (like Micarta® and phenolic plastics) never change, age, or check.

Another disadvantage is toughness and hardness. Organic materials like horn, shell, bone, and ivory can easily be scratched, dented, scarred, and stained. Though some are tougher than others, they are not physically strong materials. Some are brittle, some are downright delicate so special care must be used in mounting them on the handle, and the knife and handle itself must be cared for with extra consideration.

Size and shape can be another limiting factor in knife handle design. Most of these materials are derived from curved pieces, and the geometry of the knife handle must incorporated these curves to exhibit the most from the handle material. Particularly, this can limit  the width of the handle. Sections must sometimes be made thin to take advantage of the "display" area of the material, and this further threatens overall strength. That is why so many mammoth ivory handles, for instance, are used on smaller or folding knives. The curve of the tusk can not be fully applied to the handle flats if the handle is wide and large.

Horns and Antlers

Horns and antlers have been commonly used in knife handle construction for many millennia. Along with wood, horns and antlers are probably the oldest knife handle material. Horn and antler can be left rough, polished, or carved, sometimes scrimshawed, or textured. Though they are similar and often referred to in the same reference, there are some important differences. Horn is mostly a derivation of hair, actually hollow sheaths of keratin, tightly condensed and packed in a solid growth. Horns, such as cow horn and buffalo horn, are not shed annually, and commonly last the life of the animal.  Antlers are a porous bony appendage that are shed annually, so horn is a renewable resource. Elk, mule deer and white tailed deer are good examples. These "sheds" can be a valuable find in the forests of our country, and many hikers go out in the early spring just to gather shed antlers. Horns are usually more dense, antlers more porous. Some antlers are better than others. Often, the terms horn and antler and stag are interchanged, which can cause some confusion. Each one deserves some special attention:

Deer Antler (also called stag horn, deer horn): In America, this comes from the annual sheds of both the Mule Deer and the Whitetail Deer. While it can be made into a serviceable knife handle, both these types of antler are rather porous, with a fairly tough outer shell. They are probably the least expensive of handle materials on this page. Availability is good, wear characteristics are poor to fair. Appearance is fair, contaminate staining is frequent. The best use of deer antler is by careful selection of thick, heavy portions that are on the surface of the antler. The only permanent method of construction and use for a fine custom knife is to have the antler professionally stabilized. See stabilized horn below. Polishes good.

Elk Antler (also called Elk horn) Comes from the annual sheds of the American Elk, a large deer species in America. Elk antlers are definitely a step up from deer antlers, as they are thicker, stronger, with a smaller central portion of porous material, and a thicker outer density. Availability is good, wear characteristics are fair to good. Appearance is fair, contaminate staining is frequent. As with deer antler, the best use is by careful selection of thick, heavy portions that are on the surface of the antler. The only permanent method of construction and use for a fine custom knife is to have the antler professionally stabilized. See stabilized horn below. Polishes good.

Sambar Stag Antler (also called Stag, India Stag, Stag, Axis Stag, Red Stag, Cut Stag, Midnight Stag): Comes from the Sambar deer or Cheetal deer of India and the Pacific rim countries. There was an embargo on Indian Sambar that was lifted once then reapplied, but the horn is available through other countries, and supplies can be found all over the web, so don't think it is in any way "rare." Sambar stag is one of the mainstays of organic handle material in fine custom knives. Unlike deer and elk antler, it is hard, tough, solid and dense. Instead of a large porous central core, it has a small core, and a very solid outer shell, extending through most of the antler. It can have a beautiful brown textured surface, making it very attractive for knife handles, and a secure, comfortable gripping surface. Polishes well, resists most stains, good wear characteristics. It's more expensive than deer or elk antler, but well worth the expense. If you're set on having a traditional horn or antler handle, this is the material I recommend.

Antler Scales vs. Crowns (all deer, stag, and elk): There are two arrangements to antler or stag horn application on a knife handle. Scales are flat pieces slabbed from wide horns and applied to the flat sides of a full tang or folding knife handle. They are usually secured with bolster dovetails and pins. Crowns are the thick, wide flaring parts of the antler where it attaches to the animal's head. The crowns are usually used on hidden tang knives, where the tang is inserted into a hole drilled in the core of the antler and secured with pins, epoxy, or hidden methods. This creates a handle that appears as a solid piece of antler flaring out to the crown at the butt. The base of the crown is a good area for carving, engraving initials, inlaying monogram plates, gemstone, or other artwork. Antler crowns are also carved into belt buckles, conchos, or other jewelry or adornment and fittings.The only permanent method of construction and use for a fine custom knife is to have the antler professionally stabilized. See stabilized horn below.

Caribou horn: Thicker sections and a lighter color can make this an interesting handle choice. Same stability as antlers above.

Stag, horn, or antler treatments: There are ways to treat the antler before and after it is put on a knife that change the wear characteristics, the look, and the durability. One way is flame treatment, which burns the surface to a darker color, and hardens it somewhat. Stag can also be colored by stains or potassium permanganate baths. Another process is impregnation with hardening agents such as polymers, epoxies, cyanoacrilates, or sodium silicate. Probably the ultimate is pressure stabilization, done by several companies across this country, where liquid phenolics are forced under great pressures into the porosity of the material to fill any voids and essentially waterproof the material. The same process is used on hardwoods (see my wood knife handle page here). This is usually cost prohibitive on stag though, as stag is not considered as vulnerable or worthy of the treatment. I've used nearly all the treatments listed above, to some degree.

Sheep Horn and Kudu (includesMerino Sheep or Dahl Sheep): Sheep horn is just as tough as Sambar stag, but with some heavy textural lines, makes an interesting knife handle. Dark olive green to brown, with some translucency. Availability is good, horn instability is the same as other horn materials. It is often cut and steam flattened for use, which leads to questions about stability from moisture infiltration. Kudu horn is similar in shape and finish, both may be pressure stabilized and sealed.

Springbok, Impala, Gazelle, and Oryx (Gemsbok) horn: These are similar. Though they differ in shape, they have heavy ridges or texture along their length so that may in grip security when mounted on a knife handle. Their stability is the same as any antler, and they are commonly available.

Cape Buffalo Horn, Ox Horn: Another common horn used in knife handles. Very dense and fairly hard, it is much better than typical antlers. Usually black, but sometimes with white banding and other muted colors. Takes a glassy polish, some even looks like polished plastic.

Cow Horn: Though sometimes used on custom knife handles, I've only used it on stands. Variegated colors, white, gray, brown, black, olive. Polishes well.

Stabilized horn: Most of the horns and antlers listed on this page can be stabilized, that is impregnated with dyes and resinous or phenolic liquid plastics (polymers or phenolics) at high pressures, essentially making a block of plasticized horn material. Though this is done some, I think it holds a huge opportunity to stabilizing firms in the future. The materials become impervious to impregnation by liquids, they become waterproof, dimensional stability is increased, and performance is greatly improved. I suppose that the expense of stabilization is too high, and low-end knives are better suited to the use of non-stabilized horn and antler material. I do have some stabilized horn, though, and it works very well.

Ivories

Ivories are animal teeth. Ivories and tusks are unusually dense, some of the densest, hardest animal parts and remains. They are much less porous than bone, therefore last longer, are less apt to absorb liquids, and polish better. They are definitely a step up from bone and antler, but cost considerably more. However, they are not impervious to moisture damage, expansion and contraction, staining, and separation from the knife handle. I read the ad copy on one web site and the claim is when you buy a custom carved ivory knife handle, "you will own an exclusive work of art that will defy time." What? Ivory shrinks, dries, checks, cracks, and yellows. Time is an enemy of ivory, it will not defy time in any sense of the word. Such claims like this do our business and tradecraft a huge injustice. What handle material will defy time and even outlast the blade? Why, gemstone of course.

Ivories have traditionally been the most favored of animal parts for knife handles, jewelry, and accessories, so much so that the trade in ivory has reduced some animal species to near extinction. There is a lot of regulation and restrictions on ivory use, and documentation of the origin of ivory can be tedious, only for the supplier and maker, not usually for the knife client or collector.

Elephant Ivory: Elephant ivory (tusk) is a traditional fine knife handle material. It is what the general public is usually referring to when they use the singular term ivory. It is not as popular as it was 20 years ago, because of restrictions, regulations, and public sentiment over threatened elephant herds and populations. Since no elephant ivory is allowed to be shipped into or out of the United States, one must only assume that the ivory is legal, from existing stock already in the country. Ivory is dense, solid, light creamy white when freshly cut and polished, and yellowing and checking (small cracks at terminal ends) with age. All age-related changes in ivory are considered a natural part of the material, and even valued as a testament to the authenticity and age of the ivory. Old ivory has a warm, appealing patina, and the grain in the material becomes more apparent with age, thus identifying the ivory as real, and not a plastic imitation. Elephant ivory can be brightly polished, and retains a bright luster, and can be easily scrimshawed with high detail that increases the value of the knife greatly. I have, however, seen some fine ivory ruined by bad scrimshaw. Elephant Ivory carves well, and can hold high detail. Ivory is not an extremely durable handle material, and must be cared for and protected with vigilance. Several hours in the bright hot sunlight or under quartz lamps can ruin an expensive knife handle or carving. Some states prohibit trade in ivory products, so careful research of local regulations is required to prevent confiscation of your fine knife!

Mammoth Tusk, Mastodon Tusk: Also called Ancient Ivory, this is one of the most popular custom and handmade knife handle materials. These are the actual tusks of Mammoths and Mastodons that have died thousands of years ago. Sometimes called "fossil ivory" (a complete misnomer), it comes from areas where these extinct beasts have died, and their tusks have been buried soon enough to prevent consumption by other animals, and are thus preserved in soil, muck, or debris. The soils then impart color into the old ivory by thousands of years of water carrying traces of minerals into the organic ivory, staining it. The highly stained surfaces are the most valued, with browns, black, blues, rusts, and greens in the ivory. Also, some interesting staining patterns can develop. The minerals harden and stabilize the ivory to different degrees, and that probably has to do with their age and environment after burial. So these ivories are more durable than contemporary elephant ivory, but are still brittle. Again, each piece is different. They usually take a high, glossy polish, and are highly valued, increasing the worth of a custom knife tremendously.

Walrus Tusk: Current walrus tusk can only be acquired by registered Native Americans, and owned by them only, at least that is the current law. I have worked with it before for Native Americans, and I can say it's harder and tougher than elephant ivory, more durable and less brittle, and very white, taking a glassy polish. There may be current suppliers of walrus tusk, but trying to bend current regulations is not worth a legal battle or a reputation. Some laws vary, and I'm sure that imports are tightly controlled and restricted, so it depends on your state and country.

Fossil Walrus Tusk: This is much like mammoth and mastodon ivory above in color, access, and origin. It does seem tougher than the others, and has some interesting mottled patterns in the center. Be careful here, because some law enforcement types mistake ancient walrus tusk for current walrus tusk and will try to confiscate it, not knowing the difference.

Wart Hog Tusk: Easily obtainable, this curved, squarish, tooth is just about the right size for a hidden tang handle. It polishes brightly, is very hard and dense, and ivory or white colored. It scrims well, and is fairly durable.

Hippopotamus Tusk:  Hippo tusks are a great replacement for elephant ivory, and are in fact ivory just as elephant tusks are and as wart hog tusk is. They're hard, dense, and take a bright polish. They are reasonable in price and availability. The same limitations and concerns with moisture and temperature changes as well as stability are present.

Elk Ivory:  Elk, unlike other deer, have stubby rounded canine teeth in the upper part of their jaw. They are probably remnants of a time when they used canines for fighting. In North America, they are the only real available ivory. Out west, we call them "whistlers" believed to help the elk trumpet or bugle in his call. Some Native American tribes believe they possess magical properties. They are small ivory teeth used by jewelers and sometimes used as accessories in knife handles or sheath decorative ornaments. They polish, carve and scrimshaw well.

Whale's Tooth: This is the tooth  of the sperm whale, a highly prized, very expensive and rare item sometimes appearing on knife handles. Since the sperm whale is endangered and protected, and any importation of parts has been prohibited since 1973, all whale's teeth must be predated. Old (antique) whale's teeth can be found, but it would be ridiculous to put this valuable item on a knife handle, as it would have to be cut, shaped, and finished, ruining its antique value. There really is no reason to promote the use of whale's teeth on custom knife handles, as there are much more suitable, available, and appropriate ivories.

Bone

Animal bone has been used on knife handles since the dawn of time. Whether to represent the hunt and quest for game, or because it was a willing and workable raw material, or perhaps because ancient man just wondered what to do with all that extra bone lying around, it found its way to the handle. Bone is easily worked, plentiful, and fairly durable. On the modern custom knife, though, it has some problems. First, it is very porous. That means that it absorbs pretty much anything it contacts. Perhaps in ancient times, the tissues and fluids and sweat it encountered would help it stabilize, while imparting a weather resisting patina. Nowadays, no one field dresses their hamburger, or scrapes a hide to make boots for tromping through the snow after mammoth. So the bone is left to dry out, absorb atmospheric moisture and fluids from the hand, and is subject to continuous heating and cooling of the days and seasons. So, being so porous, it expands and contracts extensively, and eventually works itself loose from fittings, cracks around pins, fights any method of attachment used to fix it to a knife tang. It is much more unstable than ivory, and is therefore usually used on the cheapest of knives. Bones mounted on knife handles are often jigged. Jigging in this context is a word that comes from Scotland, and refers to any mechanical contrivance that operates by repeated jerky and reciprocating motion. So jigged bone is named for the jigging machine that cuts it. The cuts in the bone give it some tactile purchase, especially when wet, offer some visual interest, and hide grainy porosity in the finished surface.

Animal Bone is  more porous than ivory. Bone has always been a staple on factory folding knives, and has fair wear characteristics. It can be jigged (cut in a repeating pattern) to increase tactile friction and increase visual interest. Bone takes dyes well, and can be stabilized. It is generally not considered a high value handle material. Many types of bone may be used, commonly popular are including cow and giraffe bone. The only permanent method of construction and use for a fine custom knife is to have the bone professionally stabilized. See stabilized horn above.

Oosic: is the penile bone of the walrus. The bone is very strong and often large, and is easily obtainable. It has an outer hard shell that is nearly as dense as ivory, and takes a very fine polish. The smaller end of the oosic creates a fine hidden tang handle when left complete. There is considerable superstition and mojo attached to the oosic, as you can imagine. Although oosic is common, I've seen hyperinflated prices and "rarity" claimed. It can be carved, scrimshawed, and dyed. It fares better than stag, horn, and bone in longevity on the knife handle, but not as good as ivory.

Fossil Oosic: This is the penile bone of the walrus that has been buried for a long period of time and is mineralized. Similar to the mammoth or mastodon ivory above, the mineralization can vary, and it is not a true fossil, which means it has not been replaced by stone. It is more stable than recent oosic, has darker and interesting colors, and is more expensive. It's also harder to work.

Pearl, Shell, Coral

Mother of Pearl (MOP) is a common handle material for fine knives, guns and inlays and has been used in artwork for thousands of years. Also called nacre, it is the internal shell layer of select mollusks. It's chosen for its silky iridescence, and moderate toughness, but it is brittle on knife handles and must be worked and mounted with careful consideration. It's long lasting and beautiful, though in some applications can be a bit gaudy. It can be tinted about any color, and there are several choices that are commonly used and accepted in knife handles. It is moderately expensive, and has medium wear characteristics. In some designs it seems cold, not warm or substantial like ivories and hardwood. 

Gold Lip Mother of Pearl is an oyster shell, and has a rich yellow-golden color, sometimes with olive edges or streaks. Its characteristics are the same as mother of pearl and other shells, and the only real difference is the color. It sounds impressive, though when put on a knife handle to have the word "gold" in the description. I wonder if it would be so popular if it were called "yellow-brown seashell... "

Tiger Coral is an interesting coral material, due to its tan and brownish red stripes running through. Coral is not the best handle material, it is somewhat brittle and hard to mount. Like pearl, it must be well protected in the knife handle construction, to avoid chips and protect edges. Coral has been popular throughout history because it is easy to work, bright, and somewhat exotic. Watch out for limestone imitations of Tiger coral, with stripes simply painted on! Many corals are commonly dyed to produce the desired color.

--Jay