Gems Notes and Extracts Augusto Castellani, Mrs. John Brogden 1871

82 GEMS.The central point of the mines here openedis thelittle city of Tejuco (Diamantina), situated 134 leaguesfrom Rio de Janeiro, and 240 from Bahia. It is theresidence of the general-intendant, and contains upwardsof six thousand inhabitants, all employed inexcavating the mines ;which at the beginning yielded:abundantly the firsttwenty years it is calculatedthat about three million carats of rough diamonds weiedug out but the;product did not continue in the sameproportionit diminished gradually ; : in the five yearsfrom 1801 to 1806 they only yielded 23,135 carats ;andin the ten years from 1807 to 1817 but 18,000.Other mines were discovered in 1839, not far fromthese, on a very high mountain of the same province.There are also mines at Tibbigi, near San Paulo, in theprovince of Goyaz ; in the plains of Cuba ja ;in theriver of Audaya ; in that of Malkoverde, and also inBrazil.BRILLIANT.In Italy they generally denominate thatdiamond a" brilliant " which is cut on every side in many facets.With us, then, the brilliant is a diamond renderedbrilliant, that is, worked on the wheel to giveit incertain proportions planes or facets, which, accordingto the laws of optics, reflecting back luminous rays,cause the gem to shine with great brilliancy.It is not improbable that in a very remote periodthe Indians understood the method of polishing thediamond.