It was carved from catalin or another type of early plastic, realistically detailed and painted in green & creamy white with a little yellow on the tiny root fronds. If you look closely, you can see it was sculpted and painted by hand, two additional features typical for Martha Sleeper, particularly for her early designs, and the simple add-on C clasp mechanism is another feature found on her earlier pieces. I don't know the exact type of plastic because it was finished with a clear resin wash, presumably to protect the paint, so my usual Simichrome test isn't effective due to the resin overcoat. At any rate, it is very cute, a whimsical and unusual design sure to be appreciated by any Martha Sleeper fan or lover of leeks. It measures 2 1/8" at its tallest and 7/8" at its widest and is in excellent condition with minimal signs of age/wear and no notable flaws or damage except for a few missing little root fronds (which you'd never notice unless you used a magnifying glass).
The item "1930s Vtg Martha Sleeper carved Bakelite Catalin onion Leek novelty Brooch Pin" is in sale since Sunday, June 20, 2021. This item is in the category "Jewelry & Watches\Vintage & Antique Jewelry\Costume\Bakelite, Vintage Plastics\Pins, Brooches". The seller is "vintagewiseandwonderful" and is located in Greenville, South Carolina. This item can be shipped worldwide.