Like Alkane Dust, they tend to appear at random on the edges of walkways or sitting under structural outrcroppings, so be sure to keep a keen eye on them.
Garcia - Bosch and Siegler reported their findings in the article «Copper - Catalyzed Oxidation of Alkanes with H2O2 under a Fenton - like Regime,» published in the international edition of the journal Angewandte Chemie.