Kalifeldspat (Bodmer 537)
A standard material in Glazecalc's library: its oxide analysis, unity contribution and hazards.
What it is
- Kind
- Feldspars and stones
- Formula
- SiO₂ 67.05%, Al₂O₃ 17.31%, K₂O 10.67%, Na₂O 3.02%, Fe₂O₃ 0.11%, LOI 1.84%
- Also called
- Bodmer Kalifeldspat, Bodmer 537, Feldspath potassique (Bodmer)
- Sold in
- EU
- Similar materials
- Norflux Potash Feldspar (Sibelco, K 11 / LIS D75) , Potash Feldspar (Valentine Clays)
- Source
- Bodmer Ton AG technical data sheet 'Kalifeldspat', article 537 (Stand Juli 2025) (2025-07)
Potash feldspar sold by the Swiss pottery supplier Bodmer Ton, with about 10.7% K2O and 3% Na2O. Bodmer gives its melting point as 1250 °C.
Oxide analysis and unity formula
Glazecalc has the analysis of Kalifeldspat (Bodmer 537) as weight percent of the raw material. The unity contribution is the moles of each oxide in the amount of Kalifeldspat (Bodmer 537) that holds 1.0 mole of flux, which is how Glazecalc adds it into a recipe's unity formula.
| Oxide | Weight % | Unity contribution |
|---|---|---|
| SiO₂ | 67.05 | 6.889 |
| Al₂O₃ | 17.31 | 1.048 |
| K₂O | 10.67 | 0.699 |
| Na₂O | 3.02 | 0.301 |
| Fe₂O₃ | 0.11 | 0.004 |
- Equivalent weight
- 617.28
- Fired weight
- 605.92
- Loss on ignition
- 1.84%
The equivalent weight is the grams of Kalifeldspat (Bodmer 537) that hold 1.0 mole of flux. The fired weight is what is left of that after firing.
Hazards and safety
Hazards: Fine dust contains respirable crystalline silica; avoid breathing it.
Use it in a recipe
Add Kalifeldspat (Bodmer 537) to a recipe in the Glazecalc calculator to see what it does to a glaze's unity formula.