Metalwork Takes a Bow: Techniques that Enhance Gemstone Jewelry

A rectangle-shaped gold box, decorated with filigree, granulation and gems.
Modern designer Andrea Cagnetti, known as Akelo, employs Etruscan-inspired designs using both filigree and granulation in this “Addebaran” box, 1999. Working in gold, he draws from his ancient ancestors for inspiration. Courtesy of Akelo, Andrea Cagnetti. Photo by Robert Weldon/GIA

Like a supporting actor stealing the spotlight from the star, fine metalwork can outshine the gems it displays. This collection of jewelry images, with items dating from pre-Columbian times forward, illustrates filigree and granulation, openwork, hammering techniques, engraving, Florentine finish, and mokume gane – all used to create the detail worthy of an award-winning performance.

Triangle-shaped pieces with a tourmaline center drop from a diamond-shaped top with a moonstone center.
Carolyn Tyler uses granulation, filigree and repoussé in this tourmaline and moonstone ring and earrings. She creates pieces inspired by artifacts from ancient civilizations with themes in nature, mythology and tribal art. Her jewelry is fashioned in 22K gold by Balinese crafters. Courtesy of Elise Misiorowski. Photo by Tino Hammid/GIA and Tino Hammid

Filigree and Granulation

Filigree and granulation have been used since ancient times. Filigree is created by soldering fine metal wires into intricate patterns. The wires may be plain or decoratively twisted. Historically, filigree was created by applying wires to an underlying base. As the craft evolved, the base was abandoned in favor of a lighter, openwork jewelry item with a lacy appearance. The openwork style was especially popular during the 19th century.

Granulation is an ancient jewelry art in which small gold particles adhere to the surface in bead-like fashion without apparent evidence of solder. It can be applied to create textures or designs. The Sumerians first used granulation, followed by the Etruscans in Western Europe. 

Circular pin with elaborate piercings and diamond embellishments.
The eye is immediately drawn to the delicate saw-piercing openwork platinum in this diamond brooch/pendant in trefoil motif with laurel wreaths in each lobe, surrounded by honeycomb and a lace border. All edges are milligrained. Courtesy of Neil Lane, Inc., Beverly Hills. Photo by Tino Hammid/GIA and Tino Hammid


Openwork is a piercing technique that creates a pattern in the metal that lets light come through it. Saw-piercing is an openwork technique using a drill and jeweler’s saw to create a decorative motif. Upon close examination, you can see that the edges may be pressed with a milligraining tool – imagine a wood-handled pizza cutter-like tool that rolls out a small, beadlike pattern – that leaves the desired relief on the openwork metal and allows it to sparkle.

À jour, French for “to the day,” is another form of openwork created by sawing or piercing that makes it possible for light to enter from the back. The additional light enhances the gem’s scintillation and color, which improves its liveliness.

A crescent moon-shaped pin with “arms” that reach out from its center. Each “arm” holds a pearl at the end.
This moon and stars South Sea pearl pin in 18K gold features a hammered finish. Notice how the pattern of divots creates a warm glow. Although this is a modern pin, hammered finishes were particularly popular during the Arts and Crafts period. Courtesy of Leslie Weinberg Designs. Photo by Robert Weldon/GIA.


A hammered finish is a decorative treatment created by the repeated blows of a small hammer with a specialized head to create an all-over pattern of divots. Although hammering dates back thousands of years, hammered finishes were particularly popular during the Arts and Crafts period (1860s to 1920s). Repoussé or repoussage uses a hammer and punch tool to raise the reverse side and chasing is when the artisan indents the metal surface by striking the tool with a hammer.

Wide rose gold patterned bracelet features a ruby cabochon.

Hand Engraving

Hand engraving is achieved by using gravers, chisels made of hardened steel in various shapes and sizes, to create different effects. A finish graver with delicate parallel lines is used to create a textured pattern of intersecting sets of lines known as a Florentine finish.

The Buccellati design house is known for its Florentine finish, which is recognized by its rich textural quality reminiscent of fine linen or lace. Their artisans also employ piercing techniques, which are used to create the look of honeycomb, lace or webbing. Atelier Buccellati dates to 1750 when goldsmith Contardo Buccellati made jewelry. The business rose to international fame when Mario Buccellatti took the lead from the1920s–1960s. Bucellati’s techniques and tools haven’t changed since the Renaissance.

A mokume gane bead on a black gemstone necklace.
George Sawyer is one of the few masters of mokume gane and has been perfecting his art since the 1970s. Gift of George Sawyer. Photo by Orasa Weldon/GIA

Mokume gane

Mokume gane was first made in 17th century Japan by master metalworker Denbei Shoami. The scarcity of precious metals in Japan led to the invention of new alloys and chemical treatments for coloring the alloys. Mokume gane uses layers of sheet metal of various alloys fused together to create a block. Mokume gane translates closely to “wood grain metal” or “wood eye metal,” describing the way the metal takes on the appearance of natural wood grain. The process was first used to make samurai swords.

The next time you admire a piece of beautiful jewelry, inspect the detail and craftsmanship of the metalwork to appreciate how a good supporting actor will make the star – the gem – shine.

Sharon Bohannon, a media editor who researches, catalogs and documents photos, is a GIA GG and GIA AJP. She works in the Richard T. Liddicoat Gemological Library and Information Center.