March 2005 Bench | Defining Quality Quality Features for Three-Stone Rings Knowing these will help you to explain quality to customers By Mark B. Mann The three-stone ring is a popular, simple and classic design. Whether quality-checking a new ring or taking in one for service, it’s to everyone’s benefit for you to examine style, structure, gem material, metals and finish. Identifying Parts of Three-stone Rings A. Upper gallery. B. Lower gallery. C. Center stone prongs. D. Side stone prongs. E. Ring Shank. Design Variations of Three-Stone Rings Traditionally, three-stone rings feature prong-set faceted gemstones as the major design element. Designs can vary greatly, based on the material used and the size and shape of the stones, but they exhibit common features noted in this illustration: A. The center stone and setting. B. The side stones and settings. C. The shank design and function. The Center Stone Look at the center stone setting for structural security. The center stone prongs should have a 65&Mac251; to 75&Mac251; angle and should be symmetrical from each side. The lower gallery is the structural base and should be 0.75mm to 1.5mm wide. In this example, the upper gallery is slightly wider than the lower gallery. The Side Stones The side stones are arranged to maximize the view of the gemstone arrangement and minimize the visible presence of the settings. The relative size, height and angle of the side stones form a pleasing transition from the center stone to the shank. Where the stone contours align, the girdles may be set close together for maximum view. When the shapes of the three stones prevent their being in close contact, the side stones are set a bit lower and angled to bring them closer to the center. When viewed from the top, the center stone appears to overlap the side stones. These three-stone ring arrangements show examples of appropriate prong styles for various gem shapes. Creatively fashioned prongs add a custom look. The Shank The shank design supports the group of stones with a sound structure and practical features. The shank shape can keep a top-heavy ring from turning on the finger or provide a comfortable cradle for adjacent fingers. Split shanks create a lighter look and feel, while solid shanks can double as prongs or channels for setting. Here are a variety of shank styles: Split – Lighter weight and look. Split, curved out – Shows less metal; better fit for top-heavy rings. Solid – Good support; may double as prong to reduce metal. Turn the ring to inspect the sides for symmetry, adequate thickness (typically not less than 1.5 mm) and distinct finishes. Shanks may be tapered for beauty and function. Shank designs include knife-edge, half-round, flat and variations. Finally, look inside the finger hole: you should be able to read the quality mark and manufacturer’s mark easily. The base of the lower gallery should be symmetrical and well-finished. Illustrations by Lainie Mann Visual Communications, Inc. © 2005 Inspecting Three-Stone Rings By Mark B. Mann These features are essential to ensuring quality when inspecting a three-stone ring. A. The center and side stones are level and securely set. B. The culets of the gems don’t protrude into the finger hole. C. All prongs are shaped, angled and tapered evenly. D. The center stone is 65° to 75° from the lower gallery and symmetrical from each side. E. The side stones are angled from the center to maximize the overall appearance of all stones. F. If the ring is fabricated, all solder joints are complete, have no excess solder and are free of pits. G. If the ring is cast, all surfaces and metal junctions are crisp and have been finished and polished. H. The distance between the upper and lower gallery wires is even and proportionate to the ring size. I. The quality mark and manufacturer's mark are visible and easy to read. J. The inside of the ring is flat and even and free of tool marks and polish lines. Potential Problems The center stone is not level. The culet protrudes into the finger hole. Side stones are not symmetrical to the center stone. The settings are too large for the side stones. They aren’t seated in bearings, just supported by the gallery wire and trapped in the setting by the prongs. The shank is not symmetrical when viewed from the finger hole. The ring shows wear at the side and bottom. The shank design is not symmetrical on the side. Illustrations by Lainie Mann Visual Communications, Inc. © 2005