an onyx

This small gem is a deep glossy black, with a few bands of white and pale grey sweeping across its surface. It is highly polished, and seems to both absorb and reflect light at the same time.

It is an onyx.
It weighs a couple of ounces.

You identify an onyx.
It weighs two ounces, and it is worth about three lauren.
Its keywords are onyx, black, jewel, and gem.
When embedded, it can be used to weaken an enemy.