Ferrofluid
Ferrofluids are made up of tiny magnetic fragments of iron suspended in oil (often kerosene) with a surfactant to prevent clumping (usually oleic acid).
(Source: popsci.com)
Embryonic animal photographs courtesy of the National Geographic documentary “Extraordinary Animals in the Womb.”
Joey Ramone outside The Roundhouse, July 1976. This was The Ramones first appearance in England.