Setting a Marquise Diamond
Tom Weishaar
 1. Over the years I have read many articles about setting marquise shaped diamonds in chevron, “V”, tipped crowns. For what it’s worth, I would like to add my voice to this discussion. It is my practice to always use chevron tipped crowns when setting stones that have points. I think the chevron ends look better and provide more security for the stone. I was recently given the job to set this one-carat marquise diamond and I thought you might like to see the procedures I use. |
 2. I always begin a setting project by polishing a new crown before it is soldered onto a ring. This is especially important when the crown is going onto a wide ring where the shank will prevent you from polishing in between the prongs after soldering. I like to attach a wooden spindle (available through all tool catalogs) to my polishing motor and use a soft horsehair brush to polish between the prongs. The pliers shown holding this crown is a tool shown in the article by Steve Satow in the fall 2003 issue of Bench Magazine. I like many of Steve’s tools and often copy them. |
 3. After polishing the crown I solder it onto the ring. The crown and shank tweezers shown in this picture is my own design and is featured in a separate article in this issue. I have several rules for soldering that I would like to share. #1. When working with gold crowns, I always purchase a palladium alloy crown. The palladium alloy reduces the occurrence of prong shear. #2. When soldering a white crown onto a yellow ring always use white gold solder. That way if the solder runs between the prongs it will match in color. #3. I always use high quality 14 karat, hard, plumb solder for new construction. Hoover and Strong makes the best solder I have ever used. |
 4. When setting a marquise or pear shape stone, I like to open the prongs and lay the stone down into the crown until it is at the proper height. Marquise shaped stones never have the same length to width ratio. By laying the stone in the prongs I can mark where each seat is to be cut. I also like to take into account wavy or thick girdles. |
 5. When setting a marquise or pear shaped stone I always cut the seat in the chevron or V prong first. The first cut is called the “cavity” cut. The cavity is a small hollowed out area that will allow the fragile tip of the marquise to float in air while the sides of the chevron hold the girdle of the stone away from the tip. This cut is made using a small (.05 to .08 millimeter) ball bur. Be careful not to cut too deeply or you’ll go right through the chevron. This particular stone has a thick girdle at the tip so I elongated the cavity cut into an oval to accept the diamond. |
 6. The second cut to the chevron prong is called the “bearing” cut. I will use either a small 45˚ or a small 70˚ hart bur for this cut. This cut makes a small groove in the sides of the chevron prong that will accept the girdle of the marquise. A very small ball bur can also be used to make this cut, but do not use a 90˚ hart or a setting bur for the bearing cut. Both will over-cut the seat and your stone will be loose. |
7. Once the chevron prongs have been seated I place the diamond back in prongs and mark the placement for the seats in the side prongs. Marquise diamonds with their thick girdles are often difficult to set so I like to make sure the prongs are tall enough so that I can wrap them over the diamond for a secure setting job. |
 8. To cut the seats in the four side prongs I like to use a setting bur that is small enough to cut the prongs one at a time. I never cut all four prongs at the same time as you will not be able to match the angles of the diamond. After all of the seats have been cut I’ll check each prong’s seat with the diamond to make sure it fits the stone’s pavilion angle. There should be no gaps on the sides or under the girdle of the diamond. |
9. After cutting the seats I like to use a pumice wheel to smooth out any rough areas and then it’s off for another quick, touch-up polish. |
10. This view shows the prongs after all the seats have been cut. You can clearly see the cavity and bearing cuts in the end chevron prong. Each seat is clean and matched to the angle of the diamond. This crown is now ready for setting. |
