Two distinct glazes which look similar
The glaze longquan_n_song_2G_0 has higer Alumina and lower silica than
celedon_PA_Z2G_0.
Celedon_PA_Z2G_0 has higher MgO, and lower CaO than longquan_n_song_Z2G_0.
The glaze with higher Alumina, lower Silica, and lower MgO.
A full gloss, translucent glaze that is pale aqua-green with brown
speckles. The translucence results from small bubbles
The glaze with lower Alumina, higher Silica, and higher MgO, lower CaO.
A full gloss, translucent glaze that is pale aqua-green with brown
speckles. The translucence results from small bubbles
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 1750 deg F then a half hour hold at 1750 deg F
300 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 0.15
Al2O3 0.47
SiO2 3.57
molecular percent Silica 70.56%
glaze has 0.2% silicon carbide added for local reduction of iron.
K2O 0.14
Al2O3 0.40
SiO2 3.67
molecular percent Silica 70.60%
glaze has 0.2% silicon carbide added for local reduction of iron.
Note that the two glazes have nearly identical molecular fraction of SiO2.
Perhaps that is a more important contribution
The glaze longquan_n_song_Z2G_0 is derived from a molecular percent formula
given by Nigel Wood in chapter 4 of his book "Chinese Glazes".
The glaze celedon_PA_Z2G_0 is derived from the work of David Tsabar.
Glaze longquan_n_song_Z2G_0
trapped beneath the
glaze surface.
plate is 10 inches in diameter
Glaze celedon_PA_Z2G_0
trapped beneath the
glaze surface.
plate is 11 inches in diameter
oxidation firing to cone 10 in an electric kiln
Firing profiles
Up Fire profile
Down Fire Profile
Clay body is a grolleg porcelain from Tacoma Clay Art Center.
glaze compositions
Empirical Formula glaze longquan_n_song_Z2G_0 :
Na2O 0.15
CaO 0.52
MgO 0.09
ZnO 0.09
Fe2O3 0.01
Empirical Formula Glaze celedon_PA_Z2G_0
Na2O 0.13
CaO 0.44
MgO 0.20
ZnO 0.09
Fe2O3 0.01
Remarks
to the final result than the
slight differences in the empirical formula noted.