This feldspar is being imported by Laguna Clay into North America (from India). It will be marketed as the successor to G-200 feldspar and its temporary substitute, the MFEL S3470 blend (Minspar/G-200HP blend). The chemistry of this is very similar to G-200 (this has a little more K2O, a little less Al2O3 and a little more SiO2).
The manufacturers data sheet describes it as a selected white firing high grade potassium feldspar typically used in frits, ceramic glazes, sanitary ware, table ware, white glass, TV tubes etc. The data sheet calls it PF-01 Potassium Feldspar so there is some confusion about what it will be called.
The analysis supplied here has been rationalized from that supplied on the manfacturers data sheet. It specifies plus or minus values for oxides as follows:
SiO2 +/- 1%
Al2O3 +/- 0.5%
K2O +/- 1%
Na2O +/- 0.5%
CaO < 0.3%
Fe2O3 +/- 0.02%
MgO < 0.3%
TiO2 < 0.01%
LOI 1% max
Mineralogy: 65-75% Microcline
Melting temperature: 1220C (soaking time 30 minutes)
Particle size: 2% +63 microns (the data sheet lists others but this is the one being imported by Laguna Clay)
info from the Digital Fire Ceramic Materials Database