What did this acorn-shaped amber glass lens come from?

I’m trying to identify the source of an unusual acorn-shaped amber-colored glass object I found recently. It shape makes me think it was a lens of some sort. It’s about 1-1/4 inches from top to bottom and about 1-1/4 inch in diameter at its widest point. It’s shaped almost exactly like an acorn. The bottom portion is basically a paraboloid. The upper portion, or “cap”, is octagonal and slightly domed on top. There is a metal collar around the edge of the octagon; the collar doesn’t cover the top of the dome and it doesn’t extend to the lower portion of the object.

I thought it would make a nifty pendant or ornament, so I added a cover of brown beads in peyote stitch to cover the “cap” portion. Naturally, I failed to take a picture of the thing before I upcycled it, but I have a good picture of the finished “acorn,” and I’ve drawn in the original outlines. If anyone can tell me what it was, and where I might be able to get more like it, I’d appreciate it.

Picture of the “acorn” with beaded cap.
Faded, with the original outline of the object drawn in red.

Thanks!

No clue.

bumped

It looks so ornamental now you’ve added the cap, it’s hard to picture.

Did it look like a functional item? Or that it was part of something bigger?
Is there a way to put something inside the glass?

was it hollow or solid?

Could it be a top to something? A glass bottle/ decanter ?

It looks like it could be the stopper for something. Is the bottom frosted glass or is it something softer?

My initial reaction was that it was part of a drawer handle or the fob from a light chain.

The cap looks ornamental, and broken near the top.
If there were a threaded bit where it appears busted, the whole thing could be a finial for a fancy table lamp.

Good questions, all of them.

It looks like it was part of something bigger. The metal collar didn’t seem to have been made attractive in any way, so I was assuming it was strictly functional. There’s no way to put anything inside the glass - it’s solid.

It’s solid.

There’s an idea. Usually bottle stoppers are ground and have straight sides (the part that goes in the neck of the bottle, anyway), though. This is smooth all around, and the lower part is a smooth curve.

The bottom is the same smooth, shiny hard glass as the rest of the item.

I wouldn’t have though of this. I didn’t see anything that looked like an attachment for a light chain, although such a thing could have been lost before I found it.

There’s no threaded part on the piece now, and it didn’t look broken to me (although it has some bubbles in the glass and some pits, which I attributed to it having been in the dirt a while). Where do you see the broken portion?

Thanks to everyone so far!

The top of the beaded metal collar looks like there might’ve had something more to it.
You can probably tell with a close look. I can’t, from the pix.