Verified answer

It's not an ashtray, it's a smoking stand. It's incomplete, because the matching pieces are missing from the tray. The picture isn't very good, but it looks like it's been shortened (missing part of the agate, or glass), and the finial knob might have been replaced (it should match the bottom, can't tell in the photo).

Here's a similar piece, I know it's not the same, but it's more complete:

http://www.ebay.com/itm/ASHTRAY-VINTAGE-ANTIQUE-ST...

Another:

http://www.ebay.com/itm/Vintage-Chrome-Art-Deco-Li...