The information below is primarily from Pollock and from an article in the September 6, 1993 edition of Coin World by Ken Henderson.
This metallurgical trial piece was produced by the Olin Brass Corporation of East Alton Illinois in 1991 to show off their golden colored alloy at a time when the government was again looking to replace the $1 Federal Reserve Note with a dollar coin which would not have the problems as the Susan B. Anthony dollar did.
They were struck by the Roger Williams Mint in two different alloys described as copper-based clad. The Coin World article mentions one of these alloys as being 70% copper, 24.5% zinc and 5.5% nickel on a broad copper core.
For additional information on modern dollar patterns, see Mike Wallace's article on modern dollar patterns by clicking here.
Image courtesy of Philip Barnhart.