The day was windy, but sunny.  I had a customer to my shop.  He was considerate and called ahead.  A pleasant visit.  In the fall and winter, rock shop customers tend to be of the online variety.  I picked up my book Minnesota's Geology by W. Ojakangas and Charles L. Matsch once again.  I left off reading about Wisconsin glaciation, which was the last of the glacial periods and began around 75,000 years ago.  Skimming the material, I felt I didn't understand its intricacies well enough (yet) to blog about it.  

 Last week I was called dumb as a rock in one of my Facebook groups.  Or maybe it was more than a week ago.  It was a disagreement over nomenclature.  When someone is that blunt, I question myself.  Am I really dumb as rock?  I revisited my birthstone videos.  Yes, I could have googled that material and put them together.  But that's not what happened.  I carry around in my head a lot of facts and ideas.  I didn't regurgitate them from a questionable website. Even someone who uses Wikipedia as a primary source has to have some knowledge or interest, to even know where to begin.  The quality of those videos is better than I remember them.