During this second period of operation, the Mint also struck dimes, quarters, half dollars, $5 half eagles, $10 eagles and, in 1879 only, 2,325 double eagles. It should also be noted that the New Orleans Mint was used by the Federal authorities in 1907 to coin over five and a half million silver twenty-centavo pieces for the Mexican government as part of the American government's program of producing foreign coinage. The New Orleans Mint, whose coins can be identified by the "O" mint mark found on the reverse of its coinage, earned a reputation for producing coins of a mediocre quality; their luster is usually not as brilliant as those of other mints, and center areas tend to be flattened and not sharply struck. Thus, well-struck New Orleanian coinage is prized in the numismatic world today.