Old glass

I went back to do a bit more on the bathroom fit today whilst my beautiful fiancée went to jump around in the gym. I made a bit of progress but I can't do anymore now until the joiner comes and does his bit. It was supposed to be done yesterday or the day before....
I struggled to think of something to blip today and decided to give this old jar a shot. HV found it washed up on the beach a little while ago. We have no idea how old it is or where it came from, but the shape and texture interested me.