Selling a lot of 7 pieces of Sea Worm Rock / Tube Colony Stone with a total weight of 1 lb 13 oz.  Found washed ashore on Amelia Island, Nassau County, Florida.  Some have been worn by the surf to a rounded shape.   Worm rocks are made by numerous tiny marine bristle worms of the family Sabellariidae (sa - bell- AIR - id - ee). Each worm settles onto a hard, durable surface and begins to construct a protective tube out of the surrounding sand. The Sabellariid worms attach their tubes to their neighbors’ tubes, forming large colonies which grow into massive mounding reefs.  As pieces break off the reefs, they occasionally find their way to a Florida beach where they can be found scattered among shells.  Very cool rocks.  Great for aquariums or for a beach decor.  Expect Florida sand to trickle out of the holes now and then because the holes get sand in them and it doesn't all shake out at once - though I tried to shake as much sand as possible out of the holes.  Free standard shipping in the USA.