I made this piece from dozens of dead watch batteries. They were enclosed in a thin walled 24 inch by 24 inch aluminum frame, laid flat (a tedious process) and then covered with a clear resin. The piece hangs on the wall.
Watch batteries (called button batteries in the industry) have a bit of silver in them. But, many also contain very small amounts of mercury sealed inside. Mercury keeps the battery from corroding and ruining your watch, etc. In the U.S. we use about 600,000,000 button batteries per year; millions are not properly recycled.
The piece below was installed on the gallery floor, also 24 by 24 inches. Again, I was interested in the visual qualities of all these objects packed tightly together. It was also important that I was personally responsible for using all these batteries over the years (I now use mostly rechargeables). The title of the gallery show was: Similar Things In One Place. Several other pieces from that same show are also posted on this web page.