Here’s a simple stand I put together to hold up a potted plant. It’s made of Home Depot 1/4 MDF, and is about 18" high. The L-shaped legs use a box joint, and sit in through mortises in the top and bottom. It’s just held together with friction, no glue. You could add an additional solid circle on top to improve stability and hide the leg ends, but I wound up not needing it.
That’d be a great base for a hanging necklace display. I’d probably add a second layer at least to the bottom, so it’d feel more stable, and be ‘collapsible’ for market tear down and portability.
In my non-scientific test trying to twist it in my hands, it’s pretty reasonable. I wouldn’t build an axle out of it, but it didn’t rack significantly. I think it will hold up well to the torque produced by my plant.