Cornish Stone, Synthetic (Walker BA280)
A standard material in Glazecalc's library: its oxide analysis, unity contribution and hazards.
What it is
- Kind
- Feldspars and stones
- Formula
- SiO₂ 70.4%, Al₂O₃ 16.7%, Fe₂O₃ 1.5%, TiO₂ 0.2%, CaO 1.4%, MgO 0.1%, K₂O 5.8%, Na₂O 2.6%, LOI 1.3%
- Also called
- Cornish Stone - Synthetic, Cornish Stone (Synthetic), Walker BA280, Cornish Stone (Sub Blend)
- Made by
- Walker Ceramics (blend), Victoria, Australia
- Sold in
- AU
- Similar materials
- Cornish Stone (synthetic substitute) , H&G Cornwall Stone , Cornwall Stone Substitute (Laguna SG919)
- Replaces
- Cornwall Stone
- Source
- Walker Ceramics, Raw Materials - Typical Analyses (BA280 Cornish Stone Synthetic)
Walker's fluorine-free blend of minerals made to match natural Cornish stone; Walker describes it as a slightly weaker flux than feldspar, for recipes that call for Cornish stone. Also sold by Pottery Supplies Online and, as 'Cornish Stone (Sub Blend)', by Keane Ceramics. Walker prints 1.5% iron oxide, high for a Cornish stone substitute; check with Walker before relying on it.
Oxide analysis and unity formula
Glazecalc has the analysis of Cornish Stone, Synthetic (Walker BA280) as weight percent of the raw material. The unity contribution is the moles of each oxide in the amount of Cornish Stone, Synthetic (Walker BA280) that holds 1.0 mole of flux, which is how Glazecalc adds it into a recipe's unity formula.
| Oxide | Weight % | Unity contribution |
|---|---|---|
| SiO₂ | 70.4 | 8.946 |
| Al₂O₃ | 16.7 | 1.251 |
| Fe₂O₃ | 1.5 | 0.072 |
| TiO₂ | 0.2 | 0.019 |
| CaO | 1.4 | 0.191 |
| MgO | 0.1 | 0.019 |
| K₂O | 5.8 | 0.470 |
| Na₂O | 2.6 | 0.320 |
- Equivalent weight
- 763.53
- Fired weight
- 753.6
- Loss on ignition
- 1.3%
The equivalent weight is the grams of Cornish Stone, Synthetic (Walker BA280) that hold 1.0 mole of flux. The fired weight is what is left of that after firing.
Hazards and safety
Hazards: No SDS reviewed. As a feldspar and quartz type blend it will contain crystalline silica; avoid breathing the dust.
Use it in a recipe
Add Cornish Stone, Synthetic (Walker BA280) to a recipe in the Glazecalc calculator to see what it does to a glaze's unity formula.