5 Beautiful Pictures of Osmium, the Rarest Natural Earth Element
Osmium is a hard, brittle, bluish-white transition metal in the platinum family and is the densest naturally occurring element, with a density of 22.59 g/cm. According to Dvice, it's "both the densest and the rarest element that you can dig out of the Earth. It's so hard that it's used (as an alloy)
11 Stunning Green Roofs So Cool They May Turn Rush Limbaugh Into a Tree Hugger
Living roofs -- also called vegetative or green roofs -- are growing in popularity in the U.S. and are already popular in Europe. See some of the most stunning examples of green roofs in the world.