“Sea Coal” is sometimes found along the tide line in New Jersey. These wave-tumbled bits of coal are likely from sunken ships from long ago. There are many along our coast! I like to think that each piece holds a bit of history.
A piece of coal, well eroded and washed ashore is perfectly aligned with a bit of dune grass that was blown to the tide line by a strong west-wind. Together on the sand they present a trio of lovely textures and colors.
A note on the coal: a scuba dive leader once told us before a dive to look for old, worn coal on the bottom, and told that in that particular area it had come from steamers at sea; some of them lost at sea. When bits of rounded coal wash ashore, I wonder if they have come from a similar source.