@ebromb,
I can open it. It seems to be a type of "Bog iron ore" I think its a variety called GOETHITE. It was used in earliest days as an ore for iron blooming and smelting. Its often not magnetic but certain areas of those globs may have enough iron to be weakly magnetic.
USually this stuff is found near layered sandy and clay deposits and sediments near ocean or salty bay banks.