The following is reprinted from Lagunas press release which was obviously written by a Chemist
The Degussa line of pigments (CAS-No. 10218409502) consist of Zirconium Silicate incorporating Cadmium Sulphoselenide crystals . If the surface of the glaze is damaged, this coat (of zirconium) will prevent a release of the cadmium pigment. Traditional ceramic cadmium glazes contain Cadmium Sulphoselenide crystals incorporated as a pigment which are on the surface of the ceramic body. If such a glazed surface is damaged, crystals can be released along with cadmium.
The goal of Degussa s Research and Development Department when developing the inclusion pigments was to minimize the negative appearance of cadmium release. In comparison to the traditional glazes, the inclusion pigment glazes contain considerably less cadmium, namely approximately 0.15% Cd which is approximately 1/30 of the Cd content of traditional Cd glazes.
In the past, stable red stains at high firing temperatures were unknown to the ceramic industry. This gap was bridged by the inclusion pigments which are stable up to a firing temperature of 2372 degrees F and are resistant to unfavorable kiln atmospheres.
By using inclusion pigments in glazes the following additional advantages can be achieved in comparison to the traditional cadmium glazes:
The red, orange and yellow inclusion pigments can be mixed with other and blended with other colors to make new colors.
New Mexico Clay is stocking four of the colors.
These same colors are available in Translucent underglazes from Duncan and Mayco (stable to cone 10 in reduction!) and in Opaque underglaze from Mayco, Spectrum, Coyote.