Oxford Spar
A standard material in Glazecalc's library: its oxide analysis, unity contribution and hazards.
What it is
- Kind
- Feldspars and stones
- Status
- Discontinued
- Formula
- SiO₂ 70.82%, Al₂O₃ 17.35%, K₂O 8.07%, Na₂O 3.28%, CaO 0.39%, Fe₂O₃ 0.09%, LOI 0.18%
- Also called
- Oxford
- Sold in
- US
- Similar materials
- G-200 EU Feldspar , Mahavir Potash Feldspar , Potash Feldspar (Valentine Clays) , Feldspath potassique ICE 10 (Imerys Spain) , Potash Feldspar K200 (Thailand)
- Source
- Digitalfire: Oxford Feldspar
An old US potash feldspar that has been unavailable since at least the 1990s. NM Clay names G-200 EU as a substitute for Oxford; a current potash feldspar plus a little silica comes closest, since Oxford is lower in alkali and higher in silica.
Oxide analysis and unity formula
Glazecalc has the analysis of Oxford Spar as weight percent of the raw material. The unity contribution is the moles of each oxide in the amount of Oxford Spar that holds 1.0 mole of flux, which is how Glazecalc adds it into a recipe's unity formula.
| Oxide | Weight % | Unity contribution |
|---|---|---|
| SiO₂ | 70.82 | 8.098 |
| Al₂O₃ | 17.35 | 1.169 |
| K₂O | 8.07 | 0.589 |
| Na₂O | 3.28 | 0.364 |
| CaO | 0.39 | 0.048 |
| Fe₂O₃ | 0.09 | 0.004 |
- Equivalent weight
- 687.05
- Fired weight
- 685.82
- Loss on ignition
- 0.18%
The equivalent weight is the grams of Oxford Spar 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; avoid breathing the dust.
Use it in a recipe
Add Oxford Spar to a recipe in the Glazecalc calculator to see what it does to a glaze's unity formula.