Hobbies And Interests
History
Captivating imaginations for centuries, the earliest written account of diamonds dates around 500 B.C. Lapidaries---gem cutters and engravers---from India discovered that diamonds could be cut and polished by other diamonds. By 1375, several diamond cutters had formed a guild in Nümberg, Germany. Though diamonds were originally cut by hand, modern machinery now uses diamond tips and diamond powder to complete the process.
Proportion
The cut stone's proportion determines its how light enters and exits the diamond. A diamond with proper proportions directs light out of the top of the stone no matter where the light enters. An ideal proportion above the girdle---the middle or widest part---should be one-third its total weight. The two-thirds below the girdle are the pavilion. Deviating from the ideal proportion makes the stone less brilliant.
The Cut
A well-cut diamond has clean, sharp and symmetrical facets. Each diamond shape has its own characteristics that determine its quality. Diamond cutters use advanced theories of spectral behavior and mathematical calculations to create the most effective and brilliant cuts. They study the rough crystal to decide which shape best suits the rough crystal, accounting for its depth, length and inclusions (flaws) while retaining the greatest size; a shallow stone can become a trilliant while a long stone can become a marquis. Some experienced diamond cutters claim to rely on intuition, or a feeling, to determine which cut to make on which stone.
Cut Types
By far the most popular and well-researched of cuts, the round brilliant cut gives the cutter flexibility in balancing cut, color and clarity. A princess cut is a favorite for engagement rings and is traditionally square or rectangular with pointed corners. An emerald cut differs from the princess in that its pavilion's cuts have rectangular facets, creating an unusual optical aspect. An Asscher-cut is an emerald cut that is square. The marquise cut, somewhat football shaped, gives the diamond a much larger appearance. Oval diamonds carry the same brilliance as a round diamond but have length-to-width ratios between 1.33 and 1.66. Radiant diamonds are rectangular but with beveled corners. Pear, or teardrop, diamonds are brilliant-cut with length-to-width ratios between 1.45 and 1.75. Heart-shaped diamonds are popular as a symbol of love. Cushion or pillow-cut diamonds are square with rounded corners and larger facets. A newer cut is a trilliant, developed in Amsterdam, that has 25 facets on the crown, 19 on the pavilion and often is triangular or wedge-shaped.
Learning Diamond Cutting
Courses in diamond cutting may last from a few days to a few months, depending on the type and level of course. The Gemological Institute of America has compiled a list of diamond cutting schools, but the GIA does not endorse any school.