C/6 Quintessence ash glaze

Custer feldspar 44.5
Ash Berhens 33.5
Gerstley borate 11
Ball clay 11
Total 100
Bentonite 1

Na2O 0.08 Al2O3 0.33 SiO2 1.78
K2O 0.14 B2O3 0.10 P2O5 0.05
MgO 0.06 TiO2 0.01
CaO 0.72 Fe2O3 0.01

Alumina:Silica ratio is 1.00:5.37
Neutral:Acid ratio is 1.00:4.25
Alk:Neut:Acid ratio is 1.00:0.44:1.85

Expansion: 87.8 x 10e-7 per degree C
Oxides causing abnormal expansion: B2O3