Appears to be a piece of petrified wood

Jewelry Discussion
21

Take a good look at the side of the rock perpendicular to the bumpy
surface. Are there stringers that go down from the bumps through the
rock? If there are, you are looking at the weathered end of palm
wood. If there are not, it could be something else or it could be a
material that just does not show the inner composition except on a
weathered surface. Some petrified wood is that way.

Rose Alene

22 
Take a good look at the side of the rock perpendicular to the
bumpy surface. Are there stringers that go down from the bumps
through the rock? If there are, you are looking at the weathered
end of palm wood.

There do seem to be, on one side. So, I guess the consensus is palm
wood.

Noel