Desert Varnish

Added on by Derek Brady.

… I was sitting in one of Tom’s lectures in UCD a few weeks ago and was fascinated by the idea of ‘Desert Varnish’

In 1832, a young Charles Darwin was acting as assistant to the captain and unofficial naturalist aboard the HMS Beagle. As the ship was anchored off the coast of South America near San Salvador, Darwin explored the shore, where he was intrigued by rock outcroppings that glittered in the sunlight and seemed burnished. He deduced that the rocks shone because of a coating of thin layers of metallic oxides, but he could not explain how it might have been made.

It is possible that the stuff that intrigued Darwin and so many after him is the end result of some very complex chemistry. But, no one has been able to reproduce that either. And so we have it: a natural phenomenon that exists in plain sight, and that after nearly 2 centuries of study remains a mystery.

From Weird Life by David Toomey. Publisher: W W Norton & Company

Source: www.siobhanmcdonald.com