Nepheline Syenite A270
A standard material in Glazecalc's library: its oxide analysis, unity contribution and hazards.
What it is
- Kind
- Feldspars and stones
- Formula
- SiO₂ 60.2%, Al₂O₃ 23.6%, Fe₂O₃ 0.08%, CaO 0.39%, MgO 0.02%, Na₂O 10.4%, K₂O 4.85%, LOI 0.5%
- Also called
- Nepheline Syenite 270, A-270, Spectrum A-270, Nepheline Syenite A-400, Nepheline Syenite A-200, Neph Sy, Nepheline Syenite 270x
- Made by
- Covia (formerly Unimin and Fairmount Santrol; Unimin was a Sibelco subsidiary), Nephton/Blue Mountain, Ontario, Canada
- Sold in
- US, EU, AU
- Source
- Covia technical data sheet 'SPECTRUM Ceramic Fluxes', Nephton, Ontario #060 (document code SPECTRUM A-200-A-400_TDS_NEPHTON_#060_0619_CER_ENG; copy hosted by Digitalfire) (2019-06)
Silica-deficient sodium-potassium aluminosilicate (albite, microcline and nepheline) from Ontario, a stronger flux than soda feldspar. A-270 is the usual pottery grade; A-200 and A-400 have the same chemistry and differ only in particle size (A-400 is finer).
Oxide analysis and unity formula
Glazecalc has the analysis of Nepheline Syenite A270 as weight percent of the raw material. The unity contribution is the moles of each oxide in the amount of Nepheline Syenite A270 that holds 1.0 mole of flux, which is how Glazecalc adds it into a recipe's unity formula.
| Oxide | Weight % | Unity contribution |
|---|---|---|
| SiO₂ | 60.2 | 4.419 |
| Al₂O₃ | 23.6 | 1.021 |
| Fe₂O₃ | 0.08 | 0.002 |
| CaO | 0.39 | 0.031 |
| MgO | 0.02 | 0.002 |
| Na₂O | 10.4 | 0.740 |
| K₂O | 4.85 | 0.227 |
- Equivalent weight
- 441.04
- Fired weight
- 438.83
- Loss on ignition
- 0.5%
The equivalent weight is the grams of Nepheline Syenite A270 that hold 1.0 mole of flux. The fired weight is what is left of that after firing.
Hazards and safety
Hazards: Covia states there is no free crystalline silica (<0.1%), but avoid breathing the dust.
Use it in a recipe
Add Nepheline Syenite A270 to a recipe in the Glazecalc calculator to see what it does to a glaze's unity formula.