An abstract of the treatise on diamonds and pearls [electronic resource] : BY Which Its Usefulness to all who are any Ways interested in those Jewels, will sufficiently appear; and therefore addressed to the Nobility and Gentry of this Kingdom, and to the Traders in Jewels, and Manufacturers of Diamonds. To which is added, a particular account of the French King's large brilliant diamond, Together With some Remarks upon it; and a copper plate, containing two draughts of its shape, Expansion and Depth, when rough, and wrought; and another relative to the former. By the author of that treatise.