15 Steps to Success

Similar to setting a pear-shape stone, the marquise also combines two different kinds of prongs and procedures. The fragile tips of pear and marquise stones are commonly set in large “V” prongs, and the sides are held in round prongs. The techniques are not difficult, when analyzed step by step. Author and educator Alan Revere explains the details of setting a marquise.

  1. After completing the tapered-baguette settings (see “Practical Stone Setting: Part IX,” JCK , May 2005, p. 186), focus on setting the 12 mm by 6 mm marquise center stone. Now is a good time to touch up and repolish any areas that will be inaccessible after the marquise is set. As always, check the stone for damage and examine the cut. What does the girdle look like and how much does it vary in thickness? Are the cuts uniform? Are the girdle and table level? Make notes on the envelope and plan your strategy to accommodate the stone’s shape.

  2. With the stone placed on top, examine it from above and from the sides. Visualize the depth of the girdle. To a limited extent, the prongs can be moved in or out to accommodate different stone sizes. Use pliers to adjust the prongs, so that the stone sits on the inner lip of the top of all prongs. Remember, because of the angle, the stone will actually cover more of the prongs as it drops into the setting. Use a large flat file to level out the tops of the prongs in one flat plane.

  3. Taking advantage of all the tools and aids possible to increase accuracy, use dividers to mark the girdle height on all prongs. With the dividers set at the point where the girdle will sit, about 0.9 mm down from the top, scratch the lightest visible line around each prong. Taking a moment to add this optional but important visual guideline is well worth the time.

  4. With the heights marked all around, use a pair of chain-nose pliers to pull back each of the four side prongs. Grabbing the entire length, slowly move each prong out. Also make sure the prongs are straight and evenly spaced. Sometimes, if the stone has a deep pavilion, it may make contact with the gallery wire in the setting. If so, it may be necessary to remove some of the wire from the interior, so that the stone can drop in deeper. A 3 mm bud bur can be used to carve the wire on the inside, leaving a flat angled facet matching the shape of the pavilion of the stone.

  5. Focusing on the V prongs, use a 1.5 mm hart bur to cut seats for the points of the stone. With the ring firmly held in place in a ring clamp, cut straight into the center of the V at the girdle line. Move the bur to both sides and widen the cut to the edges of the V prong. It is very important to prevent the bur from spinning out of control and wrapping around the prong while doing this. You can gain control by (1) stabilizing your hands and (2) using a speed with a very light touch. Depending on the girdle thickness in different places, you might need to move the bur up and down to accommodate the shape. After the seats are cut, remove flashing.

  6. The fragile endpoints of the marquise must float within the V prongs, to protect them from pressure. In other words, the stone is held near, but never at the point, which makes no contact. It is simply too fragile. To ensure that it is safe, the point sits in a recessed area carved away with a small, 0.5 mm ball aimed directly into the point of the V. Again, wiggle the bur up and down if the stone’s girdle is thick.

  7. Next, use a 3 mm hart bur to carve seats into all four side prongs. With your hands firm and solid, bring the spinning bur very lightly into contact with each prong, one by one. To avoid grabbing, again use a higher speed and lighter touch than normal. Make the cuts about a third of the way deep into the prongs, checking for even, level, and uniform shapes. Finish at nearly 50 percent removal.

  8. Before inserting the stone, take a minute to examine and clean up all flashings and tool marks. Take your final opportunity to polish the interior. Use wax to carry the stone, placing it into the setting point first.

  9. To prepare the setting and also allow the stone to drop in, the prongs were positioned too far out. Now use a pair of large flat pliers placed directly on the outer points of the two V prongs, to bring them closer together. Depending on the specific alloy, there is some flexibility in the metal. Gently close the pliers as the prongs move together and then release. They will recoil slightly, which is fine.

  10. Close the angle of both V prongs with chain-nose pliers. Place the jaws on both sides of the V. Squeeze slowly and evenly as the angle of the V prongs, which was larger than the angle of the stone, is brought in to match. As the V is closed, the metal is pulled away from the fragile tip, which floats, so there is no contact and no danger of damage.

  11. Returning to the side prongs, use a pusher (with a 2 mm square face) to tighten them around the stone. Start with the pusher nearly horizontal and move the prongs inward until they are tight against the stone. They may recoil a little. To close in the tips, place the pusher on the top of each prong and raise the handle to direct the force downward as the tips tighten over the stone. Examine your work to ensure that there is full contact between the prongs and the stone.

  12. Saw or clip the tips of the four side prongs to the height of the table. Use a flat or a barrette needle file to shape the tips so that they are hemispherical. Finish with a cup bur to give the tips a uniform rounded shape.

  13. It’s time to shape the V prongs. Using a 4-cut barrette needle file, establish a flat facet on each side of the V. All of the facets should be identical: the same shape and size and at the same angle as the crown of the stone. The two facets should come together at a crisp straight mitered corner in the middle of the tip of the V. Finish these facets with a 6-cut file.

  14. Use a graver to create the bright cuts. These are essential to finishing, shaping, and brightening the V prongs. Use the tip of a flat graver to cut the inside of the tip of the V prong, leaving four crisp flat facets.

  15. Examine the prongs for uniformity. Search for and remove tool marks. Repolish any areas that do not have a high luster.

The procedures in this article are standard practices for bench jewelers at this time. If not executed properly, however, they can cause harm. Neither the author nor publisher is responsible for injuries, losses, or damage that may result from the use or misuse of this information.