This is the Martha Washington half dollar. The Martha Washington obverse was designed by Edward R. Grove and the reverse is by Philip Fowler. Examples are believed to have been struck as follows: Nickel J2131 Cupro-Nickel Clad J2132 with at least 4 known and illustrated above. An example was first offered in ANR's 12/03 sale and a second one was in Bowers & Merena's 7/05 sale and later reoffered in ANR's 1/06 sale. One is also known struck on a clad quarter planchet. A mint error, it was offered in Heritage 3/2003 and 8/2004 sales. To view this piece, click here. It is unknown if these were struck inside or outside the mint. 50% Silver, 50% Copper J2133 Silver Clad J2134 as used from 1965 to 1970 on the Kennedy half dollar. There are 6 examples in the Smithsonian embedded in two blocks of blue lucite along with J2101/P2081 and J2116/P2082. To view one of these blocks, click here. Pollock inadvertently lists these Smithsonian pieces as being struck in cupro-nickel clad. Columbium (type 1) J2135 Columbium (type 2) J2136 Zirconium J2137 Monel (nickel base alloy) J2138 Nickel-5% Silicon with Magnetic Core J2139 Stainless Steel (type 301-Type I) J2140 Stainless Steel (type 301-Type II) J2141 Stainless Steel (type 302) J2142 It is not known if any still exist. These dies are now used by the U.S. Mint to test various planchet sizes and alloys. They were used in 1999 to test the new "brass" planchet used on the Sacagawea dollar. To view one of these trial pieces, click here. Photo courtesy of Bowers and Merena from their July 2005 sale.