Giannis vs Polinik on the color of bronze :)

[M. Demetrius]

Polishing with abrasives makes increasingly smaller "grooves" from the grit, and gives an increasingly higher gloss, but microscopically, it will still be a rough surface. These grooves can be filled by dust, dirt, and other material, interfering with the gloss.

Burnishing flattens any of the high spots adjacent to the grooves left by abrasives, and gives a microscopically smoother surface. Hence, the object will have a shinier appearance, and less surface irregularities for impurities to enter, making a longer-lasting shine.

Polished then burnished metals will be very mirror-like.