Cone 4 #13 Transparente

Gerstley borate 20
Frit 3134 20
EPK 12
Kaolin (Calc.) 10
Silica 34
Magnesium carbonate 4
Total 100

Na2O 0.18 Al2O3 0.32 SiO2 3.52
K2O 0.00 B2O3 0.57 P2O5 0.00
MgO 0.24 TiO2 0.00
CaO 0.58 Fe2O3 0.01

Alumina:Silica ratio is 1.00:11.08
Neutral:Acid ratio is 1.00:3.97
Alk:Neut:Acid ratio is 1.00:0.89:3.53

Expansion: 60.4 x 10e-7 per degree C
Oxides causing abnormal expansion: B2O3