1st - I noticed this was your very first post - so, Welcome Aboard Britni! You didn't list your state (or country) in your profile. So, you might consider jumping over to Sub-Forum: Select Your Area.... for information (i.e., clubs, hunts, finds, legends, maps, etc.) directly related to your state (or country).
2nd - I searched Google and found ALL ABOUT THE ART AND SCIENCE OF STONE CARVING that begins with "...There are as many reasons, one supposes, for carving stone as there is for anything that offers the opportunity for artistic expression, generating an income, fulfilling a mission, satisfying a hobby inclination and/or challenging oneself in a creative outlet...more..."
Yes and yes symbols were carved in stones. Yes they have value although many stones people think are artifacts are just stones do you have any pictures.