A Treatise on Diamonds and Pearls

Jeffries was a jeweler in 18th-century London. This early work on the methods of cutting gems and evaluating them provides an important historical perspective. Jeffries' is the first book in English to describe how diamonds and pearls can be evaluated on the basis of size (weight) and cut. The 18th-century ideal emphasizing the retention of maximum weight was very different from today's notions which emphasize brilliance. The text explains cutting procedures of the period, with plates illustrating the various styles. This second edition, published only one year after the acclaimed first edition, is considerably expanded and includes information on diamonds from Brazil and diamond-cutting in India.