====== Bone China ======

**Bone China** is a type of soft-paste porcelain that is composed of bone ash, feldspathic material, and kaolin. It is defined as ware with a translucent body containing a minimum of 25% bone ash, though higher quality products often contain up to 45% to 50%.

Known for its high levels of whiteness and translucency, bone china is the strongest of the porcelain or china ceramics, having very high mechanical and physical strength and chip resistance.

{{:en:materials:bone_china.png.png?400|}}

===== 1. Characteristics =====

  * **Translucency**: When held up to a light source, bone china allows light to pass through. This is its most distinctive feature.
  * **Color**: It has a warm, milky white or ivory tone, rather than the stark "blue-white" of hard porcelain.
  * **Weight**: It is remarkably lightweight yet exceptionally strong due to the added bone ash.
  * **Resonance**: When tapped gently, high-quality bone china produces a clear, ringing sound.

===== 2. Composition and Production =====

The quality of bone china is largely determined by the percentage of animal bone ash (typically from cattle) in the clay body.

^ Component ^ Percentage (Approx.) ^ Function ^
| Bone Ash | 25% - 50% | Provides translucency and strength |
| Kaolin (China Clay) | 25% | Gives plasticity for shaping |
| Cornish Stone (Feldspar) | 25% | Acts as a flux to bind materials |

**The Firing Process:**
Bone china undergoes two separate firings:
  1. **Biscuit Firing (1250°C)**: The body shrinks and becomes vitrified.
  2. **Glost Firing (1150°C)**: A lower temperature firing to melt the glaze onto the surface.

===== 3. How to Identify Real Bone China =====

If you are a collector or buyer, use these three tests:
  - **The Light Test**: Hold the piece up to a lamp; you should clearly see the outline of your fingers through the material.
  - **The Sound Test**: Flick the rim with your fingernail; it should sustain a long, musical "ring."
  - **The Visual Test**: Look for a warm, creamy tint rather than a cold grey or blue tint.

[Image of bone china cup held up to light showing translucency]

===== 4. Care and Maintenance =====

To preserve the beauty and longevity of your bone china:
  * **Dishwasher Safety**: Most modern bone china is dishwasher safe. However, pieces with **gold or platinum rims** should always be hand-washed to avoid abrasion.
  * **Thermal Shock**: Avoid extreme temperature changes (e.g., pouring boiling water into a very cold cup).
  * **Storage**: Place felt or paper dividers between stacked plates to prevent surface scratches on the glaze.

===== 5. Notable Manufacturers =====

  * [[:en:brands:wedgwood|Wedgwood]] (United Kingdom)