OM-4 Ball Clay
A standard material in Glazecalc's library: its oxide analysis, unity contribution and hazards.
What it is
- Kind
- Clays
- Formula
- SiO₂ 59.7%, Al₂O₃ 26.3%, Fe₂O₃ 1.3%, TiO₂ 2%, CaO 0.2%, MgO 0.5%, K₂O 1.1%, Na₂O 0.2%, LOI 9.3%
- Also called
- OM4, OM #4, OM 4, Old Mine #4, Old Mine 4, Kentucky OM-4, Kentucky OM4 Ball Clay, Ball Clay (OM-4)
- Made by
- Kentucky-Tennessee Clay Company (Imerys group), Mayfield, Kentucky
- Sold in
- US
- Source
- Digitalfire Reference Library: OM #4 Ball Clay (from a data sheet dated Jan 2013) (2013-01)
A fine, plastic Kentucky ball clay, the usual US 'ball clay' in glaze and body recipes. In glazes it adds alumina and silica and helps keep the slurry suspended; it fires off-white to buff because of its iron and titanium.
Oxide analysis and unity formula
Glazecalc has the analysis of OM-4 Ball Clay as weight percent of the raw material. The unity contribution is the moles of each oxide in the amount of OM-4 Ball Clay that holds 1.0 mole of flux, which is how Glazecalc adds it into a recipe's unity formula.
| Oxide | Weight % | Unity contribution |
|---|---|---|
| SiO₂ | 59.7 | 32.180 |
| Al₂O₃ | 26.3 | 8.354 |
| Fe₂O₃ | 1.3 | 0.264 |
| TiO₂ | 2 | 0.811 |
| CaO | 0.2 | 0.116 |
| MgO | 0.5 | 0.402 |
| K₂O | 1.1 | 0.378 |
| Na₂O | 0.2 | 0.105 |
- Equivalent weight
- 3238.65
- Fired weight
- 2937.46
- Loss on ignition
- 9.3%
The equivalent weight is the grams of OM-4 Ball Clay that hold 1.0 mole of flux. The fired weight is what is left of that after firing.
Hazards and safety
Hazards: Contains crystalline silica (quartz); do not breathe the dust.
Use it in a recipe
Add OM-4 Ball Clay to a recipe in the Glazecalc calculator to see what it does to a glaze's unity formula.