Midstone

Description: Plainsman Native Clay

Oxide	Analysis	Formula
BaO	0.32%	0.01
CaO	0.23%	0.02
K2O	2.59%	0.16
MgO	0.65%	0.10
Na2O	0.06%	0.01
TiO2	0.68%	0.05
Al2O3	17.19%	1.00
P2O5	0.15%	0.01
SiO2	70.37%	6.95
Fe2O3	1.26%	0.05
MnO	0.01%	-
LOI	6.49%	n/a
Oxide Weight		554.86
Formula Weight		593.37

Notes

A unique fine grained, clean material, vitrifying and reaching very high strength at cone 8. It is well balanced and of medium plasticity and suitable as the main constituent for mid-temperature bodies and to promote vitrification in the higher ranges without adding dark color. This material is balanced enough to use by it self for pottery.

Fired Temperature, Cone 3 4 5 6 7 8
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Fired Shrinkage: 4.5% 4.8% 5.2% 5.6% 6.1% 6.0%
Absorption: 6.0% 5.0% 3.8% 2.4% 1.4% 1.0%
Fired Strength:
(lbs/ square inch) 7000 9000 10700 11600 12200

Sieve Analysis Wet Washed
(Root of 2 series) +35 +48 +65 +100 +150# +200 +325
--------------------------------------------
0.0% 0.1 0.4% 1.2% 2.0% 4.1% 11.8%

Texture: Smooth
Plastic Index (1-10): 6
Green Strength (lbs/sqaure inch): 1050
Dry shrinkage: 6.0
Dried density: 2.03
PCE: 23

Related Information

What does Goldart look like if you fire it by itself?

Goldart (left) compared to Plainsman Midstone (right). Goldart is a buff and vitreous stoneware at cone 10R. These are fired at cone 7, 8, 10 oxidation and 10 reduction (bottom to top). Soluble salts in the Goldart impart a darker coloration to the reduction fired bar). The Midstone has some coarser particles that make larger speckles in reduction.

Links

URLs	https://plainsmanclays.com/data/index.php?product=12908 Midstone Data Sheet
Typecodes	Clay Other Clays that are not kaolins, ball clays or bentonites. For example, stoneware clays are mixtures of all of the above plus quartz, feldspar, mica and other minerals. There are also many clays that have high plasticity like bentonite but are much different mineralogically.

Data

Frit Softening Point	PCE 23

By Tony Hansen
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