Cone 4 #20 Quintessence

Custer feldspar 49
Zinc oxide (Calc.) 11
Whiting 10
Strontium carbonate 9
EPK 13
Silica 6
Magnesium carbonate 2
Total 100

Na2O 0.06 Al2O3 0.33 SiO2 1.91
K2O 0.14 P2O5 0.00
MgO 0.06 TiO2 0.00
CaO 0.26 Fe2O3 0.00
ZnO 0.34
SrO 0.15

Alumina:Silica ratio is 1.00:5.80
Neutral:Acid ratio is 1.00:5.81
Alk:Neut:Acid ratio is 1.00:0.33:1.92

Expansion: 84.9 x 10e-7 per degree C
Oxides causing abnormal expansion: SrO