H&G Cornwall Stone
A standard material in Glazecalc's library: its oxide analysis, unity contribution and hazards.
What it is
- Kind
- Feldspars and stones
- Formula
- SiO₂ 77.39%, Al₂O₃ 14.06%, Fe₂O₃ 0.2%, CaO 0.42%, K₂O 3.34%, Na₂O 3.56%, P₂O₅ 0.22%, LOI 1.06%
- Also called
- Hammill & Gillespie Cornwall Stone, Cornwall Stone (H&G), H&G Cornish Stone
- Made by
- Hammill & Gillespie, Chatham, New Jersey
- Sold in
- US, EU
- Replaces
- Cornwall Stone
- Source
- Hammill & Gillespie MSDS 'H&G Cornwall Stone' (typical XRF analysis by an independent accredited laboratory; undated; hosted by The Ceramic Shop) (2014-12)
A Cornwall stone replacement from Hammill & Gillespie, with a typical makeup of about 20% quartz, 52% albite and 27% orthoclase. Unlike the real Cornish stone, which has not been quarried since 2006, it contains no fluorine.
Oxide analysis and unity formula
Glazecalc has the analysis of H&G Cornwall Stone as weight percent of the raw material. The unity contribution is the moles of each oxide in the amount of H&G Cornwall Stone that holds 1.0 mole of flux, which is how Glazecalc adds it into a recipe's unity formula.
| Oxide | Weight % | Unity contribution |
|---|---|---|
| SiO₂ | 77.39 | 12.831 |
| Al₂O₃ | 14.06 | 1.374 |
| Fe₂O₃ | 0.2 | 0.012 |
| CaO | 0.42 | 0.075 |
| K₂O | 3.34 | 0.353 |
| Na₂O | 3.56 | 0.572 |
| P₂O₅ | 0.22 | 0.015 |
- Equivalent weight
- 996.15
- Fired weight
- 985.59
- Loss on ignition
- 1.06%
The equivalent weight is the grams of H&G Cornwall Stone 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 (about 20% quartz); avoid breathing the dust.
Use it in a recipe
Add H&G Cornwall Stone to a recipe in the Glazecalc calculator to see what it does to a glaze's unity formula.