A bone pendant in the form of a fishhook or a fish
A hei is a pendant carved of bone or pounamu (nephrite jade). A matau is a fishhook. Like many modern ones, this has been "personified" into a marakihau (fabulous sea monster) or manaia (seahorse). This one is made of beef bone, but they were traditionally made of whalebone. (Nowadays, whales that died naturally, such as by stranding, are prized for this purpose.) The eyes are paua (abalone) shell. More and more New Zealanders are wearing them as a sign of pride and national identity.