Fig. 13

Areas before (a) and after (b) cleaning under magnification of 20x. Scale bar: 2000 μm. The rectangular area corresponded with the view of (c) under magnification of 50x (scale bar: 1000 μm), the oval area corresponded with the view (d) under magnification of 200x (scale bar: 200 μm), with red arrows pointing at the suspected micromelting