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Carbondale Clay

Alternate Names: Carbondale Red Clay, C-Red

Description: Deep-red-burning medium-fire clay

Oxide Analysis Formula
CaO 0.30% 0.02
K2O 0.38% 0.02
MgO 0.26% 0.03
Na2O 0.06% -
TiO2 1.03% 0.05
Al2O3 24.30% 1.00
SiO2 49.30% 3.44
Fe2O3 12.70% 0.33
LOI 11.80%n/a
Oxide Weight 370.77
Formula Weight 420.37


Manufacturer says: C-Red is a fine-grained, iron-bearing, plastic clay. Great for throwing bodies or anybody where warm color and plasticity are desired. Air floated.

A very high iron refractory clay well suited for many ceramic applications requiring bright red color. It fires to a toasty red up to about cone 3 and then turns dark red to brown (partly due to soluble salts on the surface that darken the color). This material has plasticity similar to a typical pottery clay body. Carbondale red provides formulators with an economical source of iron oxide.

Some have suggested this as a substitute for Newman Red, however, this is much more vitreous and higher in iron.

Physical data can be found on the link to the product information web page of the manufacturer.

Industrial Minerals states: "Due to the variations of naturally occurring clays and minerals which limit our quality control and the variety of applications for our products over which we have no control, our products are sold with the understanding that the user is solely responsible for determining suitability for any purpose."

Related Information

Carbondale Red fired clay bars

Top to bottom cone 5, 4, 7, 8 oxidation. This material is extremely high in iron and very red-burning.


Materials Newman Red Clay
Materials Redart
The most common commercially 200 mesh available raw terra cotta clay in North America. It fires red, has low plasticity and matures a low kiln temperatures.
Materials C-Red Clay
Materials Gage Red
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.
IMCO information on their mined clays
By Tony Hansen
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