Iron Colors - Pink
Here are two iron bearing glazes with visible pink markings.
The first, caAlSi_sh_MLi is just past sintered, not matured, yet shows that
tantalizing pink blush near the rim
There is a faint blush of pink, if one imagines sufficiently hard, on the
inside upper left wall.
This glaze has high alumina, with a silica alumina ratio less than 3.5, and
low iron concentration.
The second glaze, alex-longquan-iron-shino-Z3I, is a high alumina matte
containing a moderate level of iron.
Where did this glaze get either that grey or pink from iron?
bowl is ~ 4 inches in diameter.
bowl is ~ 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 1800 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 0.12
Al2O3 0.89
SiO2 3.11
molecular percent Silica 61.7%
K2O 0.11
Al2O3 0.67
SiO2 3.15
molecular percent Silica 64.1%
on the outside, also on the throwing
lines. A tantalizing color, but unlikely in a mature glaze at cone 10.
The pink is more visible on the outside. A
picture of the inside is included for completeness.
Where thin, it is a translucent
amber. If thicker, it is a micro-crystalline matte with crystals that are a
mixture of
grey and pink. This is most evident on the outside of the pot.
The inside at first glance is a mottled grey.
That pink a fascinating iron
hue in an oxidation firing.
Image of the glaze caAlSi_sh_MLi
inside
outside
Image of the glaze alex-longquan-iron-shino-Z3I
inside
outside
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 caAlSi_sh_MLi :
Na2O 0.34
CaO 0.53
MgO 0.01
Fe2O3 0.03
Empirical Formula alex-longquan-iron-shino-Z3I:
Na2O 0.31
CaO 0.57
MgO 0.01
Fe2O3 0.10