Zettlitz Kaolin (Sedlec Ia)
A standard material in Glazecalc's library: its oxide analysis, unity contribution and hazards.
What it is
- Kind
- Clays
- Formula
- SiO₂ 47%, Al₂O₃ 37%, Fe₂O₃ 0.85%, TiO₂ 0.2%, K₂O 1.1%, LOI 13%
- Also called
- Zettlitzer Kaolin, Kaolin Zettlitz, Sedlecký kaolin Ia, Kaolin Sedlec Ia, Sedlec Ia, Kaolin Zettlici, Zettlitz kaolin
- Made by
- Sedlecký kaolin a.s. (Božičany, Karlovy Vary region, Czech Republic)
- Sold in
- EU
- Similar materials
- China Clay , Grolleg China Clay , EPK Kaolin
- Source
- Interceram (Romania) product page 'Kaolin Zettlici for Ceramics', manufacturer code Sedlec Ia
Washed kaolin from the old Zettlitz (Sedlec) pits near Karlovy Vary, more than 90% kaolinite. It was long the reference kaolin of German ceramic chemistry, so recipes that call for 'Zettlitzer Kaolin' mean this material. Still sold to potters for glazes, engobes and porcelain.
Oxide analysis and unity formula
Glazecalc has the analysis of Zettlitz Kaolin (Sedlec Ia) as weight percent of the raw material. The unity contribution is the moles of each oxide in the amount of Zettlitz Kaolin (Sedlec Ia) that holds 1.0 mole of flux, which is how Glazecalc adds it into a recipe's unity formula.
| Oxide | Weight % | Unity contribution |
|---|---|---|
| SiO₂ | 47 | 66.986 |
| Al₂O₃ | 37 | 31.074 |
| Fe₂O₃ | 0.85 | 0.456 |
| TiO₂ | 0.2 | 0.214 |
| K₂O | 1.1 | 1.000 |
- Equivalent weight
- 8563.18
- Fired weight
- 7449.97
- Loss on ignition
- 13%
The equivalent weight is the grams of Zettlitz Kaolin (Sedlec Ia) that hold 1.0 mole of flux. The fired weight is what is left of that after firing.
Hazards and safety
Hazards: Kaolin dust; may contain a little crystalline silica (quartz). Avoid breathing the dust.
Use it in a recipe
Add Zettlitz Kaolin (Sedlec Ia) to a recipe in the Glazecalc calculator to see what it does to a glaze's unity formula.