Every now and then, a stone really stands out. This one isn’t from anywhere near Oakland, but somehow it wound up in a low wall in the front yard of a house on Pleasant Valley Court. My fellow geobloggers and geotwitterers think it must be tourmaline crystals. Click it for a larger version.
“Exotic blocks” is a phrase used in the research community for bodies of land that seem to have traveled from elsewhere to their present location.