Fig. 2
From: Close up to the surface: reflections on a preliminary forensic study of four Chinese bronze mirrors
a Surface tool marks (scratches) on Mirror 1. It can be seen that these marks go across the protruding corrosion on the mirror surface and are not beneath this corrosion. This indicates later abrasive cleaning of the reflective surface of this mirror after some corrosion products have formed. b Polishing lines (scratches) on the reflective surface of Mirror 2. Some of these have sudden sharp angled changes in polishing lines likely due to some mechanical polishing process. Here some corrosion sits on top of some of these marks indicating an older polishing process before some of the corrosion products have formed. c Polishing lines on the reflective surface of Mirror 3. There are a mixture of fine and broad parallel streaks indicating different cleaning abrasives and likely different periods of cleaning. There are a larger number of surface defects per unit area compared to mirrors 1 & 2. d A ×40 image of a region of top-level thick (~ 200 micron) green patina on the back surface of mirror 1. Evidence of strong abrasive cleaning is seen as parallel score marks on this green patina. The more corrugated surface of the metal alloy underneath where this thick patina has become detached is also clear. e A ×40 image of part of the shiny, black patina on the back surface of mirror 2 taken on one of the spiral patterns. Again, very clear evidence of strong abrasive cleaning is seen as a series of fine criss-crossing linear score marks. The fine shine on this side likely indicates recent abrasive cleaning