. Bulletin - United States National Museum. Science. CATALOGUE OF GEMS AND PRECIOUS STONES. 143 girdle, one-third, and from the girdle to the culet two-thirds of the total. The diameter of the table should be four-ninths of the breadth of the stone. When applied to other stones these proportions are more or less modified to suit their individual optical constants. DOUBLE BRILLIANT CUT. The double brilliant, or Lisbon cut, is a form with two rows of lozenge-shaped facets, and three rows of triangular-shaped facets,. Fig. 17.—The double brilliant. Top (a), side (6), and back (c) views. 74 in all
. Bulletin - United States National Museum. Science. CATALOGUE OF GEMS AND PRECIOUS STONES. 143 girdle, one-third, and from the girdle to the culet two-thirds of the total. The diameter of the table should be four-ninths of the breadth of the stone. When applied to other stones these proportions are more or less modified to suit their individual optical constants. DOUBLE BRILLIANT CUT. The double brilliant, or Lisbon cut, is a form with two rows of lozenge-shaped facets, and three rows of triangular-shaped facets,. Fig. 17.—The double brilliant. Top (a), side (6), and back (c) views. 74 in all. The figure shows top (a), side (b), and bottom (c) views of this fashion. HALF BRILLIANT CUT. The half brilliant, single, or old English cut is the simplest form of the brillliant, and is generally employed for stones too small to admit. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States National Museum; Smithsonian Institution; United States. Dept. of the Interior. Washington : Smithsonian Institution Press, [etc. ]; for sale by the Supt. of Docs. , U. S. Govt Print. Off.
Size: 2780px × 899px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience
