Possible Clues:

• Guardian of Oriental Pride, for one, found in the inner sanctum of Shell
• Part of shell found by the roofer working with lamp
• Iridescent material used in ornamentation
• Porthole frame rebuilt in iridescent material
• Ornamental material revealed by girl's mum
• Inner mollusk shell layer (3 words)
• It's far from dull as Margaret's parent
• Nacreous internal layer of a shell
• Common name for nacre
• Minnie's mama