When we broke up the rink we had some large chunks of ice remaining. As we played with them we noticed they had some funny shapes. It appears the glacier was made of small pencil shaped columns that were all stuck together. Here's a pic of what it looked like when you dropped a big chunk.
You could apply pressure on the sides of the chunks and the groups of columns would break apart into individual pieces. The columns did not have a specific pattern. They were similar but not in a crystal like way.
I did a quick search on St Google, but couldn't find anything to help me explain this phenomena. It appears the ice had strength on top (where we skated) but not on the sides when we picked up a chunk and squeezed. I know the ice formed from the top and worked down, but you could not see this pattern of columns from the top. My engineer brain is very intrigued by this, mostly because I just don't understand it.
Maybe my chemist Uncle can help me explain what this is all about?