I am both worn by a tree, and a symbol of royalty. Even a coin can describe me. What am I?

Lanky Wood Communicator tributary under the hood

When I'm just one, the way I'm called May perhaps make your blood run cold. Unless you're German - then it's fine, it won't scare you, this name of mine. But when there's more? All fun and games! Let's roll and see the numbers race.

brown and smooth, meant to soothe, though I prefer it a little more rocky. used many a way, from sauces to saute, I make things divine. alone I am fine, paired with a figurative log and ants, I am the missing piece.

I cradle blooms with quiet grace, yet hold no roots, just time and space. Glass or clay, I stand and stay, until one slip and shards betray.