The One that Got Away

Firing profiles

Up Fire profile

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

Down Fire Profile

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

Clay body is a grolleg porcelain from Tacoma Clay Art Center.

Empirical Formula glaze mazama_Z2A :

The glaze with .07 molecular fraction Phosphorus

K2O        .31
Na2O        .28
CaO        .17
MgO        .24

Al2O3        .82
Fe2O3        .24

SiO2        4.28
P2O5        .04

molecular percent Silica 67%

Remarks

If applied thickly enough, the glaze mazama_Z2A is a mixture of blacks, greens, oranges and yellows with flecks of metallic gold particles.
This can be seen on the inside of the bowl. Unfortunately, this application also results in heavy pitting,
which is why I refer to it as the one that got away.

If applied thinly, as on the outside of the bowl, the pitting is less prominent, but the exciting range of colors also is lost.
This is most evident near the foot.

The metallic luster is difficult to photograph properly. While it is less prominent on the inside, it is more evident on the outside
than seen in the above images.

This glaze is as viscous as might be expected for one with such high alumina, and low silica:alumina ratio. That high viscosity
makes movement within the glaze slow and facilitates the growth of a variety of distinctive micro-crystals.