Amethyst Whorl

The Amethyst Whorl is little more than a cheap trinket, but it serves its purpose: it may contain up to 512 G, and will fill at a constant rate of 0.5 M when worn around the neck.

Just like a Knot, the stored mana is available to the wearer's spells.

An Amethyst Whorl may be carved from a single shard, and worn around the neck by use of a simple copper and string attachment.