Cone 4 #19 Quintessence

Custer feldspar 47
Zinc oxide (Calc.) 10
Wollastonite 15
Strontium carbonate 5
Whiting 16
Magnesium carbonate 2
Total 100

Na2O 0.05 Al2O3 0.33 SiO2 1.85
K2O 0.12 P2O5 0.00
MgO 0.05 TiO2 0.00
CaO 0.42 Fe2O3 0.00
ZnO 0.28
SrO 0.08

Alumina:Silica ratio is 1.00:5.69
Neutral:Acid ratio is 1.00:5.71
Alk:Neut:Acid ratio is 1.00:0.33:1.86

Expansion: 83.3 x 10e-7 per degree C
Oxides causing abnormal expansion: SrO