MASON STAIN – ST6110 – VIOLET OF IRON

COMPOSITION – AL FE SI

This category encompasses the various chemical substances manufactured in the production of inorganic glasses. For purposes of this category, “glass” is defined as an amorphous, inorganic, transparent, translucent or opaque material traditionally formed by fusion of sources of silica with a flux, such as an alkali-metal carbonate, boron oxide, etc. and a stabilizer, into a mass which is cooled to a rigid condition without crystallization in the case of transparent or liquid-phase separated glass or with controlled crystallization in the case of glass-ceramics. The category consists of the various chemical substances, other than by-products or impurities, which are formed during the production of various glasses and concurrently incorporated into a glass mixture. All glasses contain one or more of these substances, but few, if any, contain all of them.

The elements listed below are principally present as components of oxide systems but some may also be present as halides or chalcogenides, in multiple oxidation states, or in more complex compounds. Trace amounts of other oxides or chemical compounds may be present. Oxides of the first seven elements listed* comprise more than 95 percent, by weight, of the glass produced.: Aluminum*; Boron; Calcium*; Magnesium*; Potassium*; Silicon*; Sodium*; Antimony; Arsenic; Barium; Bismuth; Cadmium; Carbon; Cerium; Cesium; Chromium; Cobalt; Copper; Germanium; Gold; Holmium; Iron; Lanthanum; Lead; Lithium; Manganese; Molybdenum; Neodymium; Nickel; Niobium; Source: Mason Color

Reference Notes – items in BOLD apply to this stain

1. Can be used as a ‘body stain’ in porcelain at high temperatures. All of the brown colors can be used as ‘body stains’ but will vary in shade considerably depending on the composition of the body and temperature at which it is fired.

1a. Use only as a ‘body stain’ Firing Temperatures can only be a rough guide. Firing at 2200 degrees F on a slow schedule may give the equivalent maturing as firing at 2300 degrees F on a fast schedule. The cycle, atmosphere and rate of cooling will affect the color.

2. Max. firing limit 2156 degrees F (1180 degrees C).

3. Max. firing limit 2300 degrees F (1260 degrees C).

4. Max firing limit 1976 degrees F (1080 degrees C).

Zinc Oxide influences the color in a glaze more than any other element.  Generally, zincless glazes should not contain magnesium oxide. Some colors containing zinc are to be used in a zincless glaze. The zinc in the color is in a combined form and will not harm the color, but free zinc oxide in the glaze can destroy the color.

5. Do not use zinc in glaze.

6. May be used with zinc or without zinc.

7. Zinc not necessary, but gives better results.

8. Best results with no zinc.

Calcium Oxide content as calcium carbonate should be between 12-15% for best color development. Adding the molecular equivalent of calcium oxide with wollastonite, a natural calcium silicate, often gives better uniformity.  The increased silica from the wollastonite must be subtracted or the glaze will have a poor surface.

9. Glaze must contain 6.7 to 8.4% CaO (12-15% CaCO3).