There are three stones that allow basically instant communication. The brighter the stones the clearer the message. A brownish red stone wouldn't be as good as a bright red one. The way these stones work is that if you get two stones and isolate them from all other stones together, the stones become bonded and now can communicate with each other. What I want to know is how would these stones affect an early civilization economy. When there is instant communication certain things become economically possible.
Red: somewhat common if you tried hard enough you could fined one . Most of the time though you would get the darker weaker variety.Only give vague emotions between two individuals.
Blue: Uncommon if one tries hard enough you could find it or get someone to find it.Gives clear emotions with and image associated with said emotion. For example: if your village was burning down and you used the stone the other person would see fire.
Purple: basically a modern cellphone that can send emotions as well. Rare and quite dangerous to get. The darker unpure variety tends to be unstable and explodes once bonded.