Vielin (pronounced Vie-lin) are a Veela's life source, like blood to humans.
Vielin, when shed, has a golden appearance and has the texture of water.
Vielin, like unicorn blood, had good and bad uses.
If the blood is taken forcefully, it will bring the bad luck. If the blood is drunk, the blood will cause the person great pain, extend their life, and age them a little faster.
Though if the blood is freely given, the affects are much better. If the blood is freely given, it can cure any disease and reverse the aging process and make you age slower.
When a Veela dies, the next of kin harvests the blood and creates a jewel of good fortune and prosperity. This jewel is called Bijoulin.