How to Care for Ivory, Horn, Bone and Antler
By: CCI - ICC
Publication Date: 4/1/2002 12:00:00 PM
Ivory, Horn, Bone and Antler
Ivory, bone, horn, and antler have been used to craft objects that run the gamut from everyday household items to intricate jewelry, carvings, and statues. The detailed scrimshaw done by 18th-century sailors is just one of many beautiful examples. With proper care these objects can last and be enjoyed for many years.
Ivory is a specialized form of tooth. The most common source is elephant tusk although other mammalian tusks (e.g. walrus, sperm whale tooth, and narwhal) have been used. A synthetic "ivory" was produced from cellulose nitrate in the late 1800s and early 1900s. Called "French" or "India" ivory, it resembles the real thing but its structure breaks down over time.
Bone looks similar to ivory but it is lighter in weight and usually not as white. A polished bone surface usually has small pits and what appears to be a lightly scratched surface; these are the exposed "tunnels" that permeate the bone.
Antler is a specialized form of bone that often has a rough textured surface.
Horn is made up of the same material found in fingernails or hooves.
Causes of Damage
Contact with the natural oils of skin or exposure to coloured materials can result in staining or darkening of ivory and bone. Over time, exposure to the environment can also produce some darkening in ivory which can be considered a patina.
Exposure to light can bleach ivory.
Insects can damage horn.
Extreme or rapid fluctuations in temperature and humidity cause small changes in dimensions of ivory, horn, bone, and antler, which can lead to cracking.
Liquids such as cleaning solution or even water can also cause damage.
Ensure that your hands are clean and dry before handling ivory, bone, horn, and antler.
Safeguard items from extreme or rapid changes in temperature or humidity; a display case will provide some protection against environmental fluctuations, dirt, and dust. Do not display ivory, bone, horn, and antler in direct sunlight, under bright lights, near heat or air-conditioning units, or near windows and exterior walls.
When storing items, wrap them in unbuffered, acid-free tissue paper or unbleached muslin and then place them in a sealed polyethylene bag (e.g. Ziploc freezer bag).
Do not use rubber-based materials (which can cause yellowing) to cushion items made of ivory.
A light dusting with a soft brush is often all that is needed to clean ivory, bone, horn, and antler objects. Ivory and horn that are in good condition (i.e. with a smooth, glossy surface) and have no applied decoration can be cleaned with a little water. Use a cotton swab (e.g. Q-tip), barely dampened, and dry the object immediately with another cotton swab or soft tissue. Do not attempt to clean porous bone or antler this way without first consulting a conservator. Do not use water on any object that is cracked or otherwise damaged. Never soak objects.
The cleaning and repair of ivory, bone, horn, and antler is a delicate procedure. If an object is very dirty or damaged, consult a professional conservator.