Phosphorus and Texture
Phosphorus added to a purple glaze created a metallic micro-crystalline
bronze glaze.
The second glaze was generated from the first by the addition of phosphorus,
turning a sedate purple adventurine glaze
The original glaze without phosphorus.
This is a full gloss dark purple black with a dusting of silvery red crystals,
that sparkles in bright light.
glaze with added Phosphorus.
This is a yellowish brown glaze with a metallic undertone, its surface is largely
covered in varigated metallic microcrystals.
The white flecks on the outside of the pot are reflections off of pinholes in
the glaze.
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 2300 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 .11
Al2O3 .56
SiO2 3.12
molecular percent Silica 63%
K2O .11
Al2O3 .56
SiO2 3.12
molecular percent Silica 62%
into a bronze glaze with
surface dominated by metallic golden micro-crystals.
Glaze iron_8_R_C10_13PSi
bowl is ~3 inches in diameter
Glaze iron_8_R_C10_13PSi_PP
The dominant color of the
micro-crystals is golden yellow, though there are reds greens and blacks, as
well.
Depending on the lighting, there is a distinct hint of lusterous
opalescence which contributes to the multicolored effect.
bowl is ~3 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 iron_8_R_C10_13PSi
Na2O .45
Li2O .25
CaO .17
MgO .02
Fe2O3 .28
Empirical Formula glaze iron_8_R_C10_13PSi_PP :
Na2O .45
Li2O .25
CaO .17
MgO .02
Fe2O3 .28
P2O5 .04