FFF Feldspar (Sibelco FFF K7-60)
A standard material in Glazecalc's library: its oxide analysis, unity contribution and hazards.
What it is
- Kind
- Feldspars and stones
- Formula
- SiO₂ 67.3%, Al₂O₃ 19.1%, Na₂O 4.9%, K₂O 7.2%, CaO 1%, Fe₂O₃ 0.1%
- Also called
- FFF Feldspar, FFF's Feldspar, Finnish Flotation Feldspar, K7 60, FFF K7-60, K760, Potclays 3428, Potterycrafts P3316, Valentine FL012, CTM 48 Feldspar, Finish Flotation, Bath Potters FFF Feldspar
- Made by
- Sibelco (Finland)
- Sold in
- UK, EU
- Source
- Sibelco ceramics product selector, feldspars for glazes and engobes (FFF K7-60, origin Finland) (2021-06)
Mixed potash-soda feldspar (about 7% K2O, 5% Na2O) from Sibelco's Finnish flotation plant. This is the 'FFF' that Potclays, Potterycrafts, Valentine and CTM sell; the name stands for Finnish Flotation Feldspar.
Oxide analysis and unity formula
Glazecalc has the analysis of FFF Feldspar (Sibelco FFF K7-60) as weight percent of the raw material. The unity contribution is the moles of each oxide in the amount of FFF Feldspar (Sibelco FFF K7-60) that holds 1.0 mole of flux, which is how Glazecalc adds it into a recipe's unity formula.
| Oxide | Weight % | Unity contribution |
|---|---|---|
| SiO₂ | 67.3 | 6.462 |
| Al₂O₃ | 19.1 | 1.081 |
| Na₂O | 4.9 | 0.456 |
| K₂O | 7.2 | 0.441 |
| CaO | 1 | 0.103 |
| Fe₂O₃ | 0.1 | 0.004 |
- Equivalent weight
- 576.94
- Fired weight
- 576.94
- Loss on ignition
- 0%
The equivalent weight is the grams of FFF Feldspar (Sibelco FFF K7-60) 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 FFF Feldspar (Sibelco FFF K7-60) to a recipe in the Glazecalc calculator to see what it does to a glaze's unity formula.