Alternate Names: f4 feldspar, KONA F4 feldspar, Kona f-4 feldspar
Shipped from Spruce Pine, North Carolina. No longer available. Minspar 200 (formerly NC4) has virtually identical chemistry to F-4 and should be a good substitute.
+100 mesh: trace
This material is prized as a porcelain ingredient because of its low iron content. It is used in casting and throwing porcelains of all types. At cone 6 for example, it is possible to make a vitreous body using 50-60%. However to get enough plasticity in such bodies, it is necessary to use ball clay or bentonite which can darken the color. If high plasticity is not essential, Macaloid and plastic kaolins can be used.
Another similar material is Nepheline Syenite.
The most common source of fluxes for high and medium temperature glazes and bodies.