Nepalese wedding necklace 

called a potey tilhari and is traditionally worn by Nepali women as a sign of married status. It fulfils the same function as a ring in the Western world.

Before a couple are married the father of the groom purchases a hollow cylinder bead of 18–24 carat gold (tilhari) and takes it to a bead seller who makes the necklace. The traditional colours for the glass beads (potey) are either vermillion red or bright green. Red is the most common colour since both red and pink are associated with good luck and fertility.

Source: Pitt Rivers Museum Body Arts | Marriage necklace