This striking art deco era dress clip is made of a black overdyed or painted plastic, possibly Bakelite, accented with a lime green plastic that might be Prystal. If you try to Simichrome test the black, you'll only pick up black from the paint/dye, which makes it impossible to verify that way. The green tests negative, which happens sometimes with Prystal. But when held at an angle in the light, the green will show a nice blue iridescence. When tested with hot water, there is a smell, but there's something slightly off about it, probably caused by the overdye. The clip is chunky and nicely sized, measuring 1 1/4" x 2 1/2". The clip hardware is marked "PAT. NO. 1892918." This patent dates to 1933 (filed 1931), "A.E. Waller, Finding for a Clasp."

Condition is generally excellent, although you can see in the pics how there is verdigris damage to the clasp hardware. I cleaned the clasp after photographing it as well as I could, but there is definite plating discoloration and loss that is not reversible. The plastic is mostly in great shape, but there's a little blip on the lime green that could be from a hot pin test. The clasp hardware is secure.