Facets: Part Art, Part Engineering

 By Margi Jenks

  One of our Crater Gem and Mineral Show vendors will be demonstrating the process of faceting gem stones.  The show is part of the Prospector’s Gemboree here at the Crater of Diamonds State Park.  It will be held on Saturday and Sunday, May 21^st and 22^nd from 8:30 AM to 4:30 PM.  This demonstration will be a unique opportunity to watch the ancient craft of faceting gems.

  Faceting comes in two forms.  Mineral crystals naturally form facets, or faces. The crystal’s shape and the number of facets is dependent on the arrangement of atoms that form the crystal.  Diamonds generally come in three different crystal arrangements, forming a six-faceted cube, an eight-faceted octahedron, or a twelve-faceted dodecahedron.  At the Crater the shapes of our diamonds are unusual because they often come in 24-faceted tetrahexahedrons.  Depending on the precise arrangement of the crystal facets, the tetrahexahedron will either look football-shaped or almost round.  All of our naturally faceted diamonds are very beautiful, but the yellow ones are the most eye-catching.

  Over the past 500 years, jewelers and gem artists have learned how to mechanically cut facets into gem stones.  They do this in order to improve or maximize the natural reflective qualities of certain gems.  When a gemstone is perfectly cut, it will display a pleasing balance of brilliance, fire, and bright flashes of color known as scintillation.  The modern faceting process uses a machine that will hold the gem against a grinding surface.  Diamond abrasives bonded to either metal or resin forms the grinding surface.  The stone is bonded to a rod or stick that is known as the dop or the dop stick.  The machine has several ways to position the stone so that precisely angled facets can be cut.  After the faceted surface is ground, it is then polished using very fine polishing materials. 

  The artistic side of the faceting process happens when the jeweler decides the best facet angles to bring out the best result for each individual gem.  Gems can be cut into hundreds of different faceted shapes, but the most famous is the round brilliant cut.  It is used for diamonds and many colored gemstones.  The cut is shaped like a cone, so that it will reflect the most light.  It has 54 facets, and each facet is related to its neighbors by very precise angles.  The Strawn-Wagner diamond, on display at the Crater Visitor Center, is an example of a perfect round brilliant cut diamond.

  So, come to the Crater Gem and Mineral Show to watch the faceting process in action!

Search area last plowed:  April 7, 2011; Most recent significant rain:  May 1, 2011

Total diamonds found in 2011: 206

Diamonds registered for April 24-April 30, 2011 (100 points = 1carat): 

April 24 - Maria Garcia, Lincoln, AR, 26 pt. brown, 10 pt. brown; Janet Keller-Gleason, St. John, KS, 21 pt. white; Tracie Mayes, Fayetteville, AR, 74 pt. white

April 25 - Sam Johnson, Murfreesboro, AR, 65 pt. yellow

April 26 - Tony Bruss, Sterling Heights, MI, 8 pt. white

April 27 - Beth Gilbertson, Salida, CO, 8.66 ct. white; Alan Humpfer, Schererville, IN, 11 pt. brown; Stacy Drake, 3 pt. yellow; Cliff Tanner, Windsor, MO, 4 pt. white

April 28 - David Midlick, Woodridge, IL, 16 pt. yellow

April 29 - Russell Anderson, Knoxville, IA, 1.32 ct. white; Mary Payken, Midland, TX, 6 pt. white

April 30 - Casie Dehart, New Orleans, LA, 1.52 ct. brown; Nick Dater, Glenn Rose, AR, 27pt. yellow; Brian Casey, Greers Ferry, AR, 16 pt. yellow; David & Ann Dixon, Garland, TX, 16 pt. white