... particles powder ( Ag )Appearance: Silver nanoparticles are black, no other color mixed, ball shape, no obvious agglomerate.It is anti-virus ... impurities includes elements such as B,Al,Si,Cr,Mn,Fe,Co,Cu,Mo,W,P,C,S. We offer at your ... metal box. nano sliver particles powder Cu Ag Bi Ni Fe Zn Sn