- 1珍珠母（家具、樂器上的螺鈿，用的就是這層東西）
Mother-of-pearl is the hard, smooth, shiny lining inside some shells — oysters, , . It looks pale, often white or cream, but when you turn it in the light a soft rainbow runs across it. People cut it into buttons, beads, jewellery, and tiny inlaid pictures on boxes, furniture, and instruments. Though actually, it is not a kind of pearl. It is the shell's inner coat; a pearl may grow in that same kind of shell, which is why the old name treats the lining as the “mother.” Jewellers and craftspeople still say mother-of-pearl; the science word is the same stuff, just less everyday.
From the word’s history
Calque of Latin māter perlārum; possibly because the shell is the 'mother' in which pearls form.
仿拉丁文 māter perlārum「珍珠之母」；可能指孕育珍珠的貝殼。
組成A calque of Latin māter perlārum, “mother of pearls.” The nacre-lined shell is the belly — the “mother” — in which pearls are produced. The first part was perhaps also mixed, in popular imagination, with an old word mother meaning “dregs,” but the pearl-mother picture is the one that stuck.