Unidentified liquid

Unidentified Liquid is amembers-only quest item which, after being identified as Nitroglycerin, is used in the Digsite Quest to make Chemical compound along with ammonium nitrate, ground charcoal and arcenia root to blow up bricks blocking the path below digsite. It is obtained by using a vial on the barrel with a skull mark on it near the panning point, and can brought to archeology expert to learn that it's nitroglycerin.