The Basics on Stone Guitar Picks

These picks start out as big chunks of raw rock from a variety of different stones/gemstones, including agate, jade, tiger's eye, Jasper and many others. They are sliced close to the desired thickness. Then Each pick is ground on diamond abrasive wheels to the desired shape and thickness, and then polished to a super smooth finish. The edges are beveled and polished to produce a smooth clean playing edge. Some stone picks also have grips etched into them to help keep them in place.

HOW DO THEY COMPARE TO PLASTIC ONES??
On average, stone picks are more durable than the plastic ones. The average plastic pick begins to wear out quickly with repeated use, the sounds gets quieter and you can hear a definite change in the tone.I would sometimes go through a plastic pick in less then a month. Stone picks do not wear out, soften, or fray at the edges, so the quality of the sound stays the same throughout the life of the pick. But durable does not mean indestructible, and it is possible to chip or crack a stone pick if you drop it or manage to brake a thinner gauge pick. Thou it is stronger than glass, you should treat a stone pick with the same kind of care. If you do, it can last a life time.
I always keep my picks in a protective case. The thinnest gauge picks can snap, so don't put them in your back pocket when you sit down they can break. Be careful not to drop the pick on a hard surface because it is possible to chip or crack it.
So with that said the stone picks are actually cheaper then the plastic ones in the long run. for what you would spend on the plstic ones over a years time could get you a couple of stone ones each year.