textured acicular crystals
Several glazes which have acicular crystals in a glossy matrix.
The iron spotting results from the addition of 1% red iron oxide. Without
iron, these glazes are enamel white,
These four glazes have similar composition, and sufficiently close in
appearance that it seems likely that
Note that the glossy matrix is crazed, though a member of this family with
dense micro-crystals won't show it.
bowls are ~ 4 inches in diameter
150 deg F an hour to 250 deg F
400 deg F an hour to 1800 deg F
300 deg F an hour to 2050 deg F
120 deg F an hour to 2310 deg F with a hold of 20 minutes at 2310 deg F
300 deg F an hour to 1900 deg F then a 2 hr hold at 1800 deg F
300 deg F an hour to 1750 deg F then a 1 hr hold at 1750 deg F
50 deg F an hour to 1700 deg F then a three hour hold at 1700 deg F
25 deg F an hour to 1650 deg F then a one hour hold at 1650 deg F
K2O 0.11
Al2O3 0.62
SiO2 3.12
molecular percent Silica 64.9%
K2O 0.12
Al2O3 0.58
SiO2 3.04
molecular percent Silica 64.8%
K2O 0.09
Al2O3 0.58
SiO2 3.06
molecular percent Silica 65.2%
K2O 0.12
Al2O3 0.58
SiO2 3.06
molecular percent Silica 64.9%
if the iron were sourced differently,
likely these glazes could be pale ivory, without iron spotting.
the family of glazes to which these
belong contains a semi-matte micro-crystalline glaze with desired properties.
Note also that a thicker application will
generally show more of the glossy substrate, than a thin application.
Images of the glazes
glaze jingdezhen-FeMg-Z3L
inside
outside
glaze jingdezhen-FeMg-Z3L-0
inside
outside
glaze jingdezhen-FeMg-0MAlk
inside
outside
glaze jingdezhen-FeMg-Z3P-0
inside
outside
oxidation firing to cone 10 in an electric kiln
Up Fire profile
Down Fire Profile
Clay body is a grolleg porcelain from Tacoma Clay Art Center.
glaze compositions
Empirical Formula jingdezhen-FeMg-Z3L:
Na2O 0.49
CaO 0.26
MgO 0.14
Fe2O3 0.02
P2O5 0.04
Empirical Formula jingdezhen-FeMg-Z3L-0:
Na2O 0.42
CaO 0.29
MgO 0.17
Fe2O3 0.02
P2O5 0.05
Empirical Formula jingdezhen-FeMg-Z3L-0MAlk :
Na2O 0.31
CaO 0.29
MgO 0.31
Fe2O3 0.01
P2O5 0.04
Empirical Formula jingdezhen-FeMg-Z3P-0 :
Na2O 0.36
CaO 0.29
MgO 0.23
Fe2O3 0.02
P2O5 0.05