Is it a rock, a stone or a pebble?

When you look at this picture what do you see? What does it bring to mind?

I found this rock/stone/pebble while sitting on the sea wall at the Tauranga Marina the other day watching the world go by.

I wondered if the rock used to be a part of a bigger rock. I wondered if it was man made or how it was created. I wondered how old it was and what it weighs. I wondered what its composite materials were?

When you look at it what do you see?

Do you think I should try and sell it on Trade Me?

I post another day about what I thought after I wondered all these things. (Maybe)