50 State Quarters to form what is known as a "mule". Only sixteen of these specimens, produced on dollar planchets, escaped from the mint. A 2005 Minnesota double die quarter, as well as a 2005 Minnesota quarter with extra trees (another die error), have both triggered numismatic interest. An unusual die break on some 2005 Kansas quarters created a humpback bison. Relatively more common are Kansas quarters bearing the motto "IN GOD WE RUST." The United States produces proof coinage in circulating base metal and, since 1992, in separately sold sets with the dimes, quarters, and half-dollars in silver. For the silver issues,
Four Thirds system Annual Convention and Trade Show, the Four Thirds consortium consisted the following companies: This does not imply a commitment to end user products by each company. Historically, only Leica, Olympus, and Panasonic have produced bodies. Olympus and Leica/Panasonic have made dedicated Four Thirds lenses, and Sigma makes adapted versions of their "DC" lenses for APS-C format DSLRs. Kodak once sold sensors to Olympus for use in their Four Thirds bodies, but the newer Olympus Four Thirds cameras used Panasonic sensors. The majority of Four Thirds System cameras and Four Thirds lenses are made by Olympus. Many Four Thirds cameras use