Quantcast
  We apologize for any slow response. This will be fixed before October 31st Portal logo
Login/Register
Bactrian Gold Treasure from Afghanistan, coming soon....
/gemstones/king-natural-history/page_377 - 2
 

Vitrum Annulare, Pastes

Vitrum Annulare, Pastes Page of 453 Vitrum Annulare, Pastes Text size:minus plus Restore normal size   Mail page  Print this page
VITRUM ANNULARE.
369
yet in all the other kinds, except as to hardness, (hoy are far outdone by the modern Parisians. I transcribe from Burbot's ' Traité des Pierres Précieuses ' the ingredients and proportions for making the most important species (article Strass) :—
Strass, so called from the German chemist who invented it, is the brilliant White Paste, the material of Paste Diamonds. It will be seen that, coloured by different metallic oxides, it repro­duces the other gems. Barbot gives several recipes for its com­position ; but they have, as far as the Diamond is concerned, been superseded by a quite recent discovery of the ingenious Parisian chemists. By a mixture of borax (as yet a secret) a paste, the "diamant do bore," is produced as hard as quartz, defying the file, and when set in real gold (as such now are) not to be distinguished by the most practised eye from true brilliants.
ENAMELS.
Enamels, though the same in composition as pastes, differ in the mode of application. The vitreous mass is ground fine, and then, mixed with gum-water, is applied with a brush to the sur-
Vitrum Annulare, Pastes Page of 453 Vitrum Annulare, Pastes
Suggested Illustrations
Other Chapters you may find useful
Other Books on this topic
bullet Tag
This Page