This is another rock that came out of the wall in my yard. It weighs about 11 lbs and measures 9" across, 5 1/2" tall, and about 5" in depth. I think it is quartz but am not sure. Thank you for your help.
A couple of pointers that I am sure you have heard before.
Pick up some guidebooks on rocks. Geology, lapidary, etc. The books should help you identify a wide variety of rocks.
Join a rock club. Geology, rockhounding, lapidary. Any local club that deals in rocks. Experienced members are quite the knowledge base. Some have “secret” locations that few others know about.