Sell it to the vendor that sold you scrying stones (or any of the scrying stone vendors). They give the best prices.
Here's a nice write up. Scroll down halfway to sideshowbob's writeup (yeah stupid name, but he did a fantastic job explaining this, IMHO)
[link=http://eqiiforums.station.sony.com/eq2/board/message?board.id=items&message.id=9637&jump=true[/link]
Edited, Mon May 23 14:42:09 2005 by gossamer