C/6Quintessence ash glaze

Custer feldspar 50
Ash Berhens 20
Frit 3134 10
Gerstley borate 10
Ball clay 10
Total 100
Bentonite 1

Na2O 0.13 Al2O3 0.37 SiO2 2.29
K2O 0.17 B2O3 0.20 P2O5 0.03
MgO 0.05 TiO2 0.01
CaO 0.65 Fe2O3 0.01

Alumina:Silica ratio is 1.00:6.24
Neutral:Acid ratio is 1.00:4.13
Alk:Neut:Acid ratio is 1.00:0.57:2.34

Expansion: 85.6 x 10e-7 per degree C
Oxides causing abnormal expansion: B2O3