This is a complete 3 Medallion set by the Japanese Mint, Commemorating the 1970 Japanese World Exposition in Osaka.  The medals are copper, Sterling Silver (.925) and 18K Gold. The Gold Medal weight is .43 of a Troy Oz or .32 Troy Oz of Actual Gold Weight, based on the 18k or .75 purity. The Gold Medal also show some spots and the outer box does show wear as well. See photos for more details.