Objects were made of it in a mold and the material is fused by firing. The varied coloring suggested by semi precious stones is obtained by the positioning of different powdered ingredients in the mold. The process was known in ancient Egypt and was revived in France in 19th century, especially by the sculptor Henry Cross and his son Jean.
Other exponents of the technique were Albert Dammoouse, on 1898 and Francois Decrochemont, on 1990 – 1930 as well as Emile Gallee and Gabriel Angy-Rousseau.