found near limestone outcropping my guess? when you see wavy lines in a rock like that it usually means it was precipitate, like a stalagmite or stalactite. Calcitic probably, but that last photo looks definitely like what Sawmill Man stated flint or chert. The chunky ones you showed just look like weathered igneous lava rock (the holes in it are from gasses within the lava while it cooled, they leave pockets. If you have volcanoes in your area it makes sense, but if you don't probably was transported to your location for landscaping or another rock hound brought it home.