The distinction between ivory and bone is crucial for art collectors, law enforcement, and conservationists. Whether it’s an antique artifact, a decorative object, or a piece of jewelry, correctly identifying the material is essential for preserving its historical and cultural significance. While both ivory and bone are derived from animal remains, they possess distinct characteristics that allow for reliable identification.
One of the most prominent differences between ivory and bone lies in their microscopic structure. Ivory, obtained from the tusks of elephants, consists of dentin, a mineralized tissue with a distinctive cross-hatched pattern known as Schreger lines. Under magnification, these lines appear as a series of parallel and interconnected ridges that intersect at right angles. Bone, on the other hand, lacks this characteristic pattern and exhibits a more fibrous structure with longitudinal Haversian canals.
Another critical distinction is the texture and weight of ivory compared to bone. Ivory typically feels smoother and more uniform to the touch due to its dense, compact structure. Additionally, ivory possesses a higher specific gravity than bone, meaning it weighs more relative to its size. By holding and examining the object in question, one can gain valuable clues about its composition. However, it’s worth noting that some synthetic materials can mimic the appearance and feel of ivory, making further examination techniques necessary for conclusive identification.
Physical Properties
**1. Weight and Density**
Ivory is a dense material, considerably heavier than bone. The specific gravity of ivory ranges from 1.7 to 1.9, while that of bone is typically around 1.3. This difference in density is primarily due to the higher mineral content of ivory.
**2. Hardness**
Ivory is significantly harder than bone on the Mohs scale of mineral hardness. Ivory falls between 2.5 and 3 on the scale, while bone ranges from 2 to 2.5. This means that ivory can scratch bone but not vice versa.
**3. Texture**
Ivory has a smooth, uniform texture, while bone may have a more grainy or porous surface. When polished, ivory exhibits a lustrous finish, whereas bone typically has a duller appearance.
**4. Color**
Ivory is typically white or cream in color, but it can also range from pale yellow to brown. The color of ivory is influenced by factors such as age, exposure to sunlight, and the species of animal from which it was obtained. Bone, on the other hand, is typically white or off-white in color.
**5. Translucency**
Ivory is translucent, meaning that light can pass through it. This property allows ivory to be carved into delicate, intricate designs that appear to glow when held up to the light. Bone, however, is opaque and does not transmit light.
**6. Chemical Composition**
Ivory is primarily composed of dentin, a hard, calcified tissue that is also found in teeth. Bone, on the other hand, is primarily composed of collagen, a protein that gives bone its flexibility.
Density and Weight
Bone and ivory are both hard materials derived from animals. However, they have different densities and weights, which can be used to distinguish between them.
Bone
Bone is a relatively lightweight material, with a density of about 1.85 grams per cubic centimeter. This means that a bone of a given size will be lighter than a piece of ivory of the same size.
Ivory
Ivory is a denser material than bone, with a density of about 2.05 grams per cubic centimeter. This difference in density is due to the fact that ivory contains a higher concentration of minerals, such as calcium phosphate. Ivory is harder and more durable than bone, and it is often used for making jewelry, carvings, and other objects.
The following table summarizes the key differences between the density and weight of bone and ivory:
| Material | Density (g/cm³) | Weight (for a given volume) |
|---|---|---|
| Bone | 1.85 | Lighter |
| Ivory | 2.05 | Heavier |
Texture and Grains
When handling an object suspected of being made from ivory or bone, the surface will feel characteristically different. Ivory’s surface is usually smooth and polished while bone tends to feel slightly rougher with a bone’s porous surface that can feel like sandpaper to the touch.
Staining and Discoloration
Ivory tends to yellow with age, taking on a richer tone over time. Bone, on the other hand, will often become duller and more brittle with age.
Grain Patterns
The grain pattern of ivory and bone can also help determine the type of material. Ivory has a very fine, even grain, while bone has a more random, irregular grain pattern. Additionally, ivory’s grain is usually straight, while bone’s grain can be curved or wavy.
| Ivory | Bone | |
|---|---|---|
| Texture | Smooth and polished | Slightly rough and porous |
| Grain Pattern | Fine and even | Random and irregular |
| Grain Direction | Straight | Curved or wavy |
Surface Patterns
Examining the surface patterns of ivory and bone can provide valuable clues in identification:
Grain Patterns
Ivory has a distinct grain pattern that resembles small, closely packed tubes. These tubes run parallel to the length of the tusk, creating a linear pattern. In contrast, bone typically exhibits a more irregular grain pattern with less prominent tubes.
Schreger Lines
Schreger lines are microscopic ridges that cross the grain pattern in a diamond-shaped pattern. These lines are characteristic of ivory and can be seen under magnification. Bone does not usually exhibit Schreger lines.
Haversian Canals
Haversian canals are small, circular or oval channels that run perpendicular to the grain pattern. They are more numerous and visible in bone than in ivory.
Trabeculae
Trabeculae are thin, bony struts that form a honeycomb-like structure within bone. They are not present in ivory.
Table: Surface Pattern Comparison
| Characteristic | Ivory | Bone |
|---|---|---|
| Grain Pattern | Linear, with small tubes | Irregular, with less prominent tubes |
| Schreger Lines | Diamond-shaped ridges | Absent |
| Haversian Canals | Less numerous, less visible | More numerous, more visible |
| Trabeculae | Absent | Present |
Smell and Feel
Smell: Ivory has a distinct, musty smell that is often compared to old paper or cardboard. Bone, on the other hand, has a more neutral smell, or may have a slight oily odor. To check the smell, gently rub the surface of the object with a damp cloth and then sniff the cloth.
Feel: Ivory is typically smooth and cool to the touch, while bone is often rougher and warmer. The surface of ivory is also harder than bone and will not scratch easily. To test the hardness, gently scratch the surface of the object with your fingernail. If it scratches easily, it is likely bone.
Visual Inspection
In addition to smell and feel, you can also use visual cues to identify ivory from bone.
| Ivory | Bone |
|---|---|
|
White or cream-colored |
White, yellow, or brown |
|
Smooth surface with fine grain |
Rough surface with coarse grain |
|
Hard and dense |
Soft and porous |
|
No visible pores |
Visible pores |
|
Translucent |
Opaque |
How To Identify Ivory From Bone
Ivory and bone are both natural materials that have been used for centuries to create a variety of objects, from jewelry to furniture. While they can look similar to the untrained eye, there are actually a few key differences that can help you to tell the two materials apart.
Color: Ivory is typically a creamy white color, while bone can range in color from white to yellow to brown. The color of bone can also vary depending on the age of the animal, with older bones being darker in color.
Texture: Ivory has a smooth, polished surface, while bone has a more porous surface with visible pores. Ivory is also harder than bone, so it will not scratch as easily.
Shape: Ivory is typically carved into a variety of shapes, while bone is more commonly used in its natural form. Bone can be cut and shaped, but it is not as easy to work with as ivory.
Weight: Ivory is denser than bone, so it will feel heavier in your hand. A piece of ivory that is the same size as a piece of bone will weigh more.
If you are still unsure whether a piece of material is ivory or bone, you can take it to a jeweler or other expert for identification.
People also ask about How To Identify Ivory From Bone
How can you tell the difference between ivory and plastic?
Ivory is typically harder than plastic, so it will not scratch as easily. Ivory also has a more porous surface than plastic, with visible pores. Plastic is often smooth and shiny, with no visible pores.
Is it illegal to own ivory?
In many countries, it is illegal to own ivory. The ivory trade is regulated by the Convention on International Trade in Endangered Species (CITES), which aims to protect endangered species from over-exploitation. Some countries allow the sale of ivory that was obtained before CITES was established, but it is important to check the laws in your country before buying or selling ivory.
How can I tell if my ivory is real?
If you are unsure whether your ivory is real, you can take it to a jeweler or other expert for identification. There are a few tests that can be used to determine whether ivory is real, such as the scratch test and the burn test. The scratch test involves scratching the ivory with a sharp object. If the ivory is real, it will not scratch easily. The burn test involves burning a small piece of ivory. If the ivory is real, it will burn with a black flame and produce a strong odor.
