Authors:

You know, when most girls say they want a big rock, they don't mean, you know, literally a big rock." "Very amusing, my sarcastic friend. It's not a rock, precisely. All Shadowhunters have a witchlight rune-stone.

Cassandra Clare (2011). “Cassandra Clare: The Mortal Instrument Series (4 books): City of Bones; City of Ashes; City of Glass; City of Fallen Angels”, p.279, Simon and Schuster
You know, when most girls say they want a big rock, they don't mean, you know, literally a big rock. Very amusing, my sarcastic friend. It's not a rock, precisely. All Shadowhunters have a witchlight rune-stone.