Answer:
Where jewelry pierces your head.
A tiny bead, like fragile glass, strung along a cord of grass.
Small, containing light, You'll need it in the dark, It will provide that spark, and shine into the night. Will light up any pyre, 'Cause it can help make a fire.
What is often returned, but never borrowed?
What object has keys that open no locks, space but no room, and you can enter but not go in?
What is big and yellow and comes in the morning, to brighten mom's day?