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How to Facet Garnets

Garnets come in almost all colors of the rainbow. Pomegranate-shaded red Bohemian, golden spessartite, violet-orange almandine, ruby-red pyrope, plum to pink rhodolite, lemony green to brown grossular, brilliant green tsavorite, and highly collectible green demantoid garnets fascinate collectors. Color-changing garnets, like pricier alexandrite, delight gem enthusiasts. Artful cutting adds value to less-than-perfect garnet crystals. Precision and fancy cuts make ideal crystals even more valuable. Acquire inexpensive rough and tools to shape easy-to-facet garnets. Sell or trade faceted gemstones to collectors at rock and gem shows.

Things You'll Need

Garnet rough
Jeweler's loupe (10x or higher)
Jeweler's tweezer
Faceting head
Faceting machine
Gem polish
Cutting instructions for each shape (rose-cut, Portuguese-cut, etc.)

Instructions

- 1
  Shape the garnet crystal using a faceting head. Select a cutting design, such as the Tic Tac, for instructions about the dimensions, angles and facet positions. The Tic Tac design offers a simple shape -- a modified rectangle. Use the faceting head to form the outline. Grind the stone with a lap, a grinding disc for the faceting machine. According to the Tic Tac diagram, cut the primary facets for the pavilion. The pavilion forms the base of the gemstone. P1, P2, P3, P4 and P5 form the pavilion on the gem-cutting diagram. Use a finer lap to smooth the facets, then polish the facets with a dedicated polishing lap.
- 2
  Turn the crystal so that the garnet's pavilion faces down and the crown faces up. Change the lap to a coarse-grind disc. In the Tic Tac design, C1 and C2 create contrast facets for the "X" faceting design you're creating on the crown. Cut C1 and C2 to the girdle edge, or the plane separating the crown from the pavilion. Mark the crown facets without cutting too deeply. Change the lap to a fine-grind disc to complete each facet. Use the polishing lap to buff the facets. After fine-grinding and polishing the facets, pass a square of silk over the stone. The silk shouldn't catch on any rough edges. Fine-grind until the facets pass the smoothness test.
- 3
  Practice cutting a "mogul" facet design if you're brand new to gem cutting. Mogul-cuts allow the cutter to place facets in the stone without shaping or symmetry design concerns. Lining up the gemstone's pavilion, crown, table and girdle will come with practice. The Tic Tac design requires a total of 25 facets on the gemstone and 8 at the girdle plane. The round brilliant cut, often used for diamonds and other gemstones, has 57 or 58 facets.
- 4
  Contact the Gemological Institute of America (GIA) for more information about the fine art of gem faceting. Alternatively, find a rock and gem club in your area to identify an established gem cutter with whom to study faceting techniques. Plan to spend from $2,000 to $4,000 for a faceting machine, attachments and tools.

Gemology