Aventurine. 1. From strass, 500 gr.; scales of iron, 100 gr.; black oxide of copper, 50 gr.; fuse until the black oxide of copper is reduced to the reguline form, then allow the mass to cool very slowly, so that the minute
crystals of metal may be equally diffused through it. Has a rich golden iridescence.
2. As the last, but submitting oxide of chromium for the protoxide of copper. Appears brown, filled with countless gold spangles; or, when mixed with more paste, of a greenish grey, filled with green spangles.
Beryl. (Douault-Wiéland.) Strass, 3456 gr.; glass of antimony, 24 gr.; oxide of cobalt, 11⁄2 gr. See Aqua Marina.
Carbuncle. See Garnet.
Chrysolite. From strass 7000 gr.; pure calcined sesquioxide of iron (‘trocus martis’), 65 gr.
Cornelian. 1. (Red.) From strass, 7000 gr.; glass of antimony, 3500 gr.; calcined peroxide of iron, 875 gr.; binoxide of manganese, 75 gr.
2. (White.) From strass, 7200 gr.; calcined bones, 250 gr.; washed yellow ochre, 65 gr.
Diamond. 1. From rock crystal (purest), 1600 gr.; borax, 560 gr.; carbonate of lead (pure), 3200 gr.; oxide of manganese, 1⁄2 to 1 gr.; powder each separately, mix them together, fuse the mixture in a clean crucible, pour the melted mass into water, separate any reduced lead, and again powder and remelt the mass.
2. Pure silica, 150 gr.; pure litharge, 250 gr.; borax and nitre, of each 50 gr.; arsenious acid, 21 gr.