Out of the blue After evaporating some of the solvent from his reaction, Michael Hollerbach spotted these branching black crystals emerging in the beaker that held his blue-green concentrated mixture. The color of the liquid phase stems from copper residue in the reaction. Hollerbach, who is a graduate student in Simon Blakey's lab at Emory University, can't reveal the identity of this late intermediate, but he says it's part of his research on carbon-hydrogen bond functionalization using organometallic chemistry. He tells C&EN, "I took the photo because it allowed me to show my group that sometimes crude reactions can be pretty as well!" Submitted by Michael Hollerbach. Follow him on Twitter @HollerbachChem Do science. Take pictures. Win money. Enter our photo contest here. Related C&EN Content:Chemistry in Pictures: Carpet of nanoflowers Chemistry in Pictures: Crude fluorescence Chemistry in Pictures: Dandelions and darkness.