IF you have any mercury from wrecks its best to store in a glass mason-jar with tight fitting metal-lid with seal. Put water on top of the mercury and it can't evaporate. We've picked up a small amount on a wreck (lost 1875) near Pt. Sur on the Monterey coast many years ago and did exactly that. Also just took possession of a quart jar from a friend and storing it the same way while trying to find someone knowledgeable to take off our hands. Friend felt it had gold in it but we've been told ANY gold in the jar would form a amalgam. Thought about making a retort to purify it but just isn't worth the effort. Been a PIA as the stuff is so toxic IF spilled. One story I've read is the miners in the 1849 California Gold Rush would use it in the pan to capture their fines and then they placed the amalgam nugget into a baked potato alongside the campfire, then they ate the potatoe! Also remember years ago reading a National Geographic magazine and picture in the article had someone floating in a vat full of mercury. YKKKS