9a. Welded cinder
These textured red blobs are a rare formation called welded cinder. They were formed when basalt exploded out of Round Top in small hot, fragments that landed on each other and stuck together. Their "real" name also offers a good example of geologist jargon: rocks stuck together are "agglutinated," if the pieces stuck together are pebble sized, they're "lappili," and if those pebble-sized pieces are rounded, it's an "agglomerate."