The shimmering scale glimmers with a hint of Drinal's Brilliance. Desert tales have spoken of the possibility of a scale controlling the ability to change the shape of the dragon. Perhaps locating this dragon would net you a reward... or a quick death
Find someone who might be interested in the silver scale.
Take the silver scale to Siyamak in Maj'Dul at ( -248, 137, 59 ) /waypoint -248, 137, 59. Prepare for a fight! Once the person on the quest hails him, Siyamak will transform into a 64x4 Silver Dragon.