Ken Bowdon, our resident geologist, gave the Trust Talk last week. Ken lead a group of intrepid rock hounds up the Balsam Mountain Preserve golf course to the remains of a ruby mine. The mine was active until WWII and produced garnets and rubies that were used as abrasives.
Ken also pointed out rocks containing sulphur and lithium bearing minerals that were deposited from an ancient hydrothermal vent which created pegmatite deposits. Residents have reported a strong sulphur smell near the vent which still produces warm plumes of steam when water trickles down to hot rocks deep below the surface. See this article from the Sylva Herald for a history of the Ruby City mine.