C/6 Quintessence ash glaze

Custer feldspar 50
Ash Berhens 25
Frit 3134 10
Gerstley borate 10
Ball clay 5
Bentonite 2

Na2O 0.12 Al2O3 0.31 SiO2 2.00
K2O 0.15 B2O3 0.18 P2O5 0.04
MgO 0.05 TiO2 0.01
CaO 0.67 Fe2O3 0.01

Alumina:Silica ratio is 1.00:6.40
Neutral:Acid ratio is 1.00:4.19
Alk:Neut:Acid ratio is 1.00:0.49:2.06

Expansion: 88.0 x 10e-7 per degree C
Oxides causing abnormal expansion: B2O3