Re: BLACK JADE
I don't believe Tennessee is a noted jade locality and there are a lot of related (and unrelated) rocks which are commonly mistaken for jade, so the first step in determining the value of your rock would be authenticating it as jade (nephrite or jadeite).
Assuming it is in fact jade, the value of it is still highly variable depending on the quality the piece. Jade is a very tough material but it is commonly fractured due to geological processes, which reduces the value as rough to lapidaries to nil. Only a relatively small percentage of jade in the rough is considered gem grade and suitable for carving or other lapidary work.
Without authentication and a first hand inspection of the material, and possibly test cutting, it really isn't possible to give you a meaningful estimate as to the value of the rock you found. However, as a rough yardstick I can tell you I purchased several pieces of a fairly decent Australian black nephrite that was selling for under $10 per pound at the Tucson show a couple of years ago.
From Bob Keller - September 27, 2007 at 09:33:13