Indian Head gold pieces was modified by Barber, was "worthy of J.J. Audubon". Dies for the half eagle were sent to the mints in Denver and San Francisco; both western mints reported difficulties in striking the new pieces. Landis wrote to his counterparts at the other mints, advising them that the planchets, or blanks, needed to be shaved very slightly to strike properly. The new coins proved to be thinner than earlier coins of their denomination, due to the field being raised above the design. This meant that automated sorting machines could not reliably sort them when mixed with earlier coins. The new gold
Metal U.S. rose from 73g to 238g per person. Metals are inherently recyclable, so in principle, can be used over and over again, minimizing these negative environmental impacts and saving energy. For example, 95% of the energy used to make aluminium from bauxite ore is saved by using recycled material. Globally, metal recycling is generally low. In 2010, the International Resource Panel, hosted by the United Nations Environment Programme published reports on metal stocks that exist within society and their recycling rates. The authors of the report observed that the metal stocks in society can serve as huge mines above ground.