Dendrites

[605dano]

Looking at rocks under a loupe I often see dendrites. I'm not sure what minerals make them. Some are probably manganese or iron oxides or iron sulfides or gold. I've taken some pics with a usb microscope and would be curious to know what you think they may be.

 

[Goldwasher]

is it an actual inclusion ? or within cracks?

if its in the cracks I say its organic growth

the black does look like manganese