Historical clue formulations

• Mollusk with an iridescent inner shell — 2020-07-06
• Sea snail with a mother-of-pearl shell — 2018-04-23
• Another name for an ear shell — 2018-03-17
• Mother-of-pearl source — 2016-12-13
• Mother-of-pearl source — 2016-10-23
• Ornamental shell source — 2015-06-30
• Awabi, at a sushi bar — 2013-12-12
• Mother-of-pearl source — 2007-08-27
• Mother-of-pearl source — 2006-03-01
• Mother-of-pearl source — 2005-01-04
• Mother-of-pearl source — 2003-04-05
• Marine rock-clinger — 2002-07-27
• Sea-ear — 1998-12-11
• Ornamental shell — 1997-12-13
• Sautéed fish dish — 1997-09-07
• Mother-of-pearl source — 1997-07-02
• Mother-of-pearl source — 1997-05-11
• Seafood order — 1994-03-03