The term "costume jewelry" was first coined in the Art Deco era, which started in the 1920s and lasted until World War II. Also known as "streamline moderne," Art Deco embraced industrialization whereas Art Nouveau rejected it. Inspired by the Bauhaus and Cubist schools of art, as well as Mayan ruins and King Tut's tomb, Art Deco was all about rigid geometric symmetry, abstraction, and smooth, straight lines, as well as edgy new materials like chrome, steel, platinum, and plastics like Bakelite.
Deco style was a different sort of rebellion: The flapper, known as "la garçonne" in France, represented a new level of freedom for women—to be sexually adventurous and androgynous, wear their hair short, smoke openly, and show off their bare legs and arms. Coco Chanel, one of the biggest influencers of the flapper look, introduced a series of bold "statement" accessories shaped like large flowers and frogs, meant to be worn as art rather than symbols of wealth.
Around the same time, Hobé was making big, dramatic jewelry with rhinestones for the costumes of the "Ziegfeld Follies," which may have something to do with the name "costume jewelry." Elsa Schiaparelli quickly followed with a line of Dada-inspired jewelry using large, fake gemstones.
While celluloid had been used to imitate tortoiseshell, jade, coral, wood, and horn, the new plastic resin known as Bakelite—which came in bold colors like Apple Juice, Butterscotch, and Salmon—became the go-to material for long, beaded necklaces and large, chunky bangles that emphasized thin, tantalizing flapper arms. Chrome and steel were used in brooches, necklaces, and bracelets that mimicked the movements of machines and resembled nuts and bolts.
Following the lead of fine jewelers like Cartier, emerging costume jewelers like Trifari and Coro made rhinestone brooches, dress pins, earrings, necklaces, and bracelets in abstract geometric Art Deco styles that sometimes took the shape of Mayan and Egyptian pyramids, skyscrapers, automobiles, or airplanes. Both of these costume jewelers introduced clever dress-pin sets, that could be worn separately, or together on a brooch, and these, too, came in angular Art Deco shapes. Flowers became more stylized, while jewels took on Arabic, Turkish, Aztec, and Chinese patterns.
Diamanté rhinestones were also forged in the bold new shapes mimicking fine-jewelry diamonds: baguettes, trapezoids, batons, and squares known as calibré. In the mid-1920s, black-and-white looks were particularly chic, so diamanté crystals were set with black glass or enamel, a.k.a fake onyx, in beaded necklaces and other pieces.