Grolleg China Clay
A standard material in Glazecalc's library: its oxide analysis, unity contribution and hazards.
What it is
- Kind
- Clays
- Formula
- SiO₂ 49%, Al₂O₃ 36%, Fe₂O₃ 0.8%, K₂O 1.96%, TiO₂ 0.05%, Na₂O 0.1%, CaO 0.06%, MgO 0.3%, LOI 12%
- Also called
- Grolleg, Grolleg kaolin, Grolleg china clay powder, Valentine CB003, Potterycrafts P3298, Potclays 3416-03, Bath Potters Grolleg China Clay
- Made by
- Imerys (Cornwall, UK)
- Sold in
- UK, EU, AU
- Similar materials
- Standard Porcelain China Clay , EPK Kaolin
- Source
- Valentine Clays technical data sheet 'Grolleg China Clay Powdered' (mean values) (2024-07)
Blended Cornish china clay from Imerys with very little titania and about 2% K2O, so it fires blue-white. It is the usual kaolin in UK porcelain bodies and many UK glaze recipes.
Oxide analysis and unity formula
Glazecalc has the analysis of Grolleg China Clay as weight percent of the raw material. The unity contribution is the moles of each oxide in the amount of Grolleg China 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 | 49 | 26.363 |
| Al₂O₃ | 36 | 11.414 |
| Fe₂O₃ | 0.8 | 0.162 |
| K₂O | 1.96 | 0.673 |
| TiO₂ | 0.05 | 0.020 |
| Na₂O | 0.1 | 0.052 |
| CaO | 0.06 | 0.035 |
| MgO | 0.3 | 0.241 |
- Equivalent weight
- 3232.61
- Fired weight
- 2844.7
- Loss on ignition
- 12%
The equivalent weight is the grams of Grolleg China Clay that hold 1.0 mole of flux. The fired weight is what is left of that after firing.
Hazards and safety
Hazards: Fine dust; may contain traces of crystalline silica.
Use it in a recipe
Add Grolleg China Clay to a recipe in the Glazecalc calculator to see what it does to a glaze's unity formula.