We have a Lamp Finial wood look Vintagea item.  It measures about 1 1/4" in H x about 3/4" across the bottom.  The threaded center is metal and is about 3/8" across the threaded center.  It is in nice gently used condition with a bit of wear on the very top.  We thought this was wood at first as it looks and feels like it, once looking closer there are mold lines on the sides so we believe it is a plastic to look like wood.

Lamp Finial wood look Vintage