The 20 elements that are used least often as place names (ignoring all those that are never used!).
Last post we saw a map of all the towns in North America that are named after periodic elements. This post has some more detail.
Whilst I’m confident that the sainted Leadville was named after lead (a bi-product of the silver mining industry), I’m less confident about Leader, Carbonera and Tinaia, NM. I’ll ask a linguist.