A treatise on diamonds and pearls. In which their importance is considered: and plain rules are exhibited for ascertaining the value of both; and the true method of manufacturing diamonds / [David Jeffries].

  • Jeffries, David
Date:
1751
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on diamonds and pearls. In which their importance is considered: and plain rules are exhibited for ascertaining the value of both; and the true method of manufacturing diamonds / [David Jeffries]. Source: Wellcome Collection.

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    [»] ■ thirty years a confiderable trader in them, and a manufacturer of Dia¬ monds, I have ftudioufly employed great part of my time in fearch of rules to afcertain the value of both under all circumftances, whatever be their weight and magnitude; and likewife, for manufacturing Diamonds to the greateft perfection. And apprehend¬ ing that I have fully fucceeded ; for the promotion of the commerce, and for the benefit of the publick, I have exhibited, in this treatife, means by which the inquifitive- may attain to a right knowledge in thefe matters; and more efpecially concerning thofe from one carat weight, to thofe of one hundred carats. The plates of the fizes of Diamonds, and the tables of the prizes of both, are extended no farther than to Dia¬ monds and Pearls, of that weight: They