Early Plastics in Jewelry: Celluloid, Bakelite, Casein and Their Tests
The first plastics were not cheap substitutes but wonder materials, and Bakelite bangles now outsell the gold ones beside them. Identifying celluloid, casein and Bakelite is scent-and-sound detective work, and the market pays for getting it right.
Somewhere between the Victorian naturals, jet, shell, horn, and the modern acrylics lies jewelry's first plastic age, and it is anything but junk. Celluloid imitated ivory and shell from the 1870s; casein made buttons and bangles from milk protein; and Bakelite, the 1907 phenolic, became a Deco design material in its own right, carved, laminated and coloured, with a collector market today that prices good bangles startlingly. The materials are identified by a famous battery of gentle tests, scent, sound, weight, and a polish-cloth trick, and the identification is the value.
The materials, in order of arrival
Celluloid (from c. 1870): cellulose nitrate, light as paper, moulded into combs, boxes, "French ivory" with printed grain lines, and shell imitations. Its tells: extreme lightness, warmth, moulded seams, and a camphor scent under warm friction or hot water. Its vice: chemical instability, celluloid can craze, weep and even self-destruct, and sick celluloid (vinegary smell, crystalline bloom) should be isolated from other pieces, since the decay spreads corrosive vapours.
Casein (from c. 1900): milk-protein plastic, loved for buttons, knitting needles and marbled bangles. Denser than celluloid, takes lovely mottled colours, and confesses under the hot test with a scent of scalded milk. Stable but water-shy: long soaking swells it.
Bakelite (from 1907): phenol-formaldehyde, the first fully synthetic, heavy in the hand, thermoset (it cannot be re-melted, hence no mould seams from later reworking), machinable and carvable, and the Deco era's playground: carved bangles, cherry-amber beads, laminated polka dots, figural brooches. Age has mellowed its colours, whites to butterscotch, blues to green, which collectors treat as patina, not flaw.
The test battery, gentle versions first
Weight and sound: Bakelite is notably heavy for plastic, and two Bakelite bangles tapped together give a deep clunk, celluloid clicks thinly. Warm friction: rub briskly and sniff, formaldehyde-phenolic for Bakelite, camphor for celluloid, milk for casein; the hot-water dip (a few seconds, then sniff) sharpens the same scents for stubborn pieces, used cautiously and never on celluloid with decay signs. Simichrome or 409 test for Bakelite: a cotton bud with metal polish (or certain cleaners) rubbed on an inconspicuous spot comes away yellow on most genuine Bakelite, quick, near-harmless, and the trade standard, with the caveats that black Bakelite and some surfaces test falsely negative, so scent and weight arbitrate. The hot-pin test belongs to the past: it scars pieces and risks igniting celluloid, literally, and no modern collector should use it. Under the loupe, mould seams say thermoplastic (celluloid, casein, later acrylics), machining and carving marks say worked Bakelite, and printed "grain" says imitation ivory or shell, which the shell and jet guides meet from the other side.
Market and care
Bakelite is the star: carved and laminated bangles, figural brooches and cherry-amber necklaces are seriously collected, with rarity of colour and depth of carving driving prices that regularly embarrass the gold counter, and with reproductions ("fakelite") common enough that the test battery earns its keep at every fair. Celluloid collects more gently, hair combs and boxes especially, with condition and stability paramount; casein remains the affordable charmer. Care by chemistry: keep celluloid cool, dry, ventilated and quarantined at the first vinegar whiff; keep casein out of long soaks; and keep Bakelite from harsh cleaners that dull it, a soft cloth and occasional gentle polish maintaining the glow. All three dislike heat and strong sun, and none should meet ultrasonic tanks. Treated as the design history they are, the first plastics outlast their reputation and, increasingly, their prices.
Frequently asked questions
How do I test if a bangle is Bakelite?
Weight and clunk first, then warm friction for the phenolic scent, then the polish-cloth test: metal polish on a cotton bud turns yellow on most genuine Bakelite. Combine tests; black pieces can defeat any single one.
What is the hot water test?
A few seconds' dip, then sniff: formaldehyde-phenolic means Bakelite, camphor means celluloid, scalded milk means casein. Use briefly, and never on celluloid showing decay.
Why is the hot pin test discouraged?
It scars pieces permanently and celluloid is flammable, a pin test can genuinely ignite it. Scent, weight, sound and polish tests answer without damage.
What is celluloid sickness?
Chemical decay of cellulose nitrate: vinegar smell, crazing, bloom, weeping. It is contagious in storage via corrosive vapours, so isolate sick pieces immediately.
Why did my white Bakelite turn butterscotch?
Age-patina: phenolics oxidise and mellow, whites to cream and butterscotch, blues toward green. Collectors price the mellowed colours as authentic, and originals cannot be "restored" white.
Is old plastic jewelry actually valuable?
Good Bakelite decidedly: rare colours, deep carving and laminated designs bring strong collector prices, and figurals more so. Celluloid and casein collect more affordably, condition ruling throughout.