Micro-inclusions present in the copper matrix.

<p>(a) Backscattered electron images of the cuprite inclusion (dark grey) surrounded by a lighter rim rich in As (30.7%) and Bi (20.3%); (b) white segregation rich in As (11.8%),Se (9.5%),Bi (4.2%), and Pb (13.2%). Both inclusions are about 5 μm across; (c) reflected-light optical micrograph. The total length of the fragment is 870 μm.</p>