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Plastics In Jewelry

Plastics

VULCANITE: (1842) Vulcanite is a semi-synthetic, hard, inflexible heat-treated, rubber containing sulphur. Used as an imitation for jet. It feels lighter than jet and has a slight brownish tinge and shiny rubber surface. Vulcanite jewels were molded instead of carved, and this is easy to detect.

PARKESINE: (1855) The first kind of semi-synthetic thermoplastic, a cellulose nitrate, to be used commercially. Invented by Englishman, Alexander Parkes. Used to imitate ivory, amber, tortoise-shell, horn, agate, malachite and coral.

CELLULOID: (1868) One of the first successful semi-synthetic thermoplastic, is part natural fiber, or cellulose. Its generic names, pyroxylin-camphor thermoplastic, referred to as cellulose nitrate, are clues to its makeup: cellulose fiber mixed with nitric acid to which camphor is added, and subjected to heat. Invented in United States by John Wesley Hyatt. Commercial production begins in 1872. Trade name registered in 1873. Used as a substitute for many natural materials. Its drawback is that it’s flammable.

GALALITH: (1897) The trade name for casein, which is a thermoset semi-synthetic plastic that was made from milk protein and could be polished to a high gloss. Adolph Spittler invented this plastic that could be molded by heat but was not water-resistant and tended to warp.

BAKELITE: (1908) A thermosetting (permanently sets on cooling) phenol formaldehyde resin. The first entirely synthesized plastic. Invented by Leo H. Baekeland in 1908 (patented 1909). It is tasteless, odorless, water-resistant, can be polished to a high sheen, and most important, can be colored and is not flammable. A clear version of Bakelite (trade name Prystal) was introduced in 1935 by the Catalin Corporation.

LUMARITH: (1927) The Celluloid Corporation invented A Cellulose acetate. Except for its bright colors, in appearance and use, Lumarith is the same as Celluloid, but not flammable. The Celluloid Corporation did this by substituting acetic acid (vinegar) for nitric acid and camphor. NOTE: When warmed in hot water, the two materials can be differentiated: Celluloid smells like camphor and Lumarith smells like vinegar.

LUCITE: (1937) An acrylic resin introduced by DuPont. Lucite, a thermoplastic, is water clear in its original form, but is often tinted in a wide range of transparent to opaque colors. After the second war, Bakelite was no longer cost-effective to produce, so Lucite took over in production.