Answer:

nacres

Answer	Crossword Clue
NACRES	Shell liners
NACRES	Pearly layers
NACRES	Mollusk shell materials

NACRES	Abalone products
NACRES	Buttonmakers' materials
NACRES	Button substances
NACRES	Pearly shellfishes.
NACRES	Layers of shells.
NACRES	Shellfish.
NACRES	Shellfish yielding mother-of-pearl.
NACRES	Pearly substances.

NACRES	Pearly shells
NACRES	Shellfish products
NACRES	Inner layers of some shells
NACRES	Mother-of-pearls
NACRES	Button materials
NACRES	Nautilus shell liners
NACRES	Pearly linings in mollusks
NACRES	Mother-of-pearl materials

NACRES	Mother-of-pearl sources
NACRES	Iridescent substances
NACRES	Iridescent coatings of some shells
NACRES	Materials from mollusk shells