“At the Corundum Hill Mine (near Highlands), various shades of ruby gem corundum have been found,” the U.S. Geological Survey reported in 1906. However, though the gems were similar to the red rubies ...

While analyzing some of the world’s oldest coloured gemstones, researchers from the University of Waterloo discovered carbon residue that was once ancient life, encased in a 2.5 billion-year-old ruby.

In this video Derek and I drive all the way up to North Carolina to go hunting for Ruby and Sapphire Corundum crystals at the world famous Propst Farm near Lincolnton, NC. This was my first time ...

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in ...

THE three works cited below give much new and valuable information concerning the mode of occurrence, the processes of mining, and the uses of corundum. As the mineral is of growing economic value, ...

LARGE crystals of corundum have been grown for many years by the flame-fusion process originated by Verneuil 1. Crystals coloured by small amounts of chromium, titanium, vanadium and other transition ...