What is a small catch or fastening held or closed by means of a spring, or one which closes with a snapping sound, as the catch of a bracelet, necklace, clasp of a book, etc called?

snap — A small catch or fastening held or closed by means of a spring, or one which closes with a snapping sound, as the catch of a bracelet, necklace, clasp of a book, etc. (Webster's 1913.)