noun
cowrie; cowry
Refers to cowrie shells, especially the chocolate cowrie (Mauritia mauritiana). Often used in contexts of traditional games or as a charm for safe childbirth.
祖母はコヤスガイをお守りとして持っていた。
My grandmother kept a cowrie shell as a charm.
海岸で
I found a rare cowrie shell on the beach.
宝貝 is a broader term for cowrie shells in general, while コヤスガイ often refers specifically to the chocolate cowrie or shells used as amulets.
The name 子安貝 (lit. 'child-safe shell') comes from the traditional belief that cowrie shells bring safe childbirth. The exact historical derivation is uncertain.