Related Clues:

• Marine substance, often forms reefs
• Hard substance formed from skeletons of tiny sea creatures
• Hard pink substance formed by skeletons of tiny sea creatures
• Deep pink 11 across
• Shakespeare: 'Full fathom five thy father lies, of his bones are . . . . . made'
• Pinkish-red colour
• Marine substance, often forms reef
• Marine polyps, often forms reefs
• Substance formed by skeletons of tiny sea creatures
• It grows in water, in a manner of speaking, after a century
• This build-up in the water takes a century, in a manner of speaking
• Are shortly in the fuel from the bottom of the sea
• After a century, in a manner of speaking, it might make an island
• See, it's spoken for one sort of island
• What's in mine are shortly all that's in 13 across