Now, however, the mottled soaps, blue and grey, are produced by working colouring matter, ultramarine for blue, and manganese dioxide for grey, into the soap in the frame, and mottling is very far from being a certificate of excellence of quality.
Chaptal for a cheap colouring matter, as bright as ultramarine and capable of standing the heat of the porcelain furnace.
In 1828 he was awarded the prize offered by the Societe d'Encouragement pour l'Industrie Nationale for a process of making artificial ultramarine with all the properties of the substance prepared from lapis lazuli; and six years later he resigned his official position in order to devote himself to the commercial production of that material, a factory for which he established at Fleurieux sur Saone.
It has been suggested that ultramarine is a compound of a sodium aluminium silicate and sodium sulphide.
In a deep-coloured stone the colour may be resolved, by the dichroscope, into an ultramarine 1 Indirectly from Gr.