By Valentina Dimitrievska in Skopje The story of the Macedonian ruby begins in a small jewellery store in the heart of Skopje ...

This trip starts with a long drive to North Carolina and a simple goal: find ruby and sapphire corundum crystals at Propst Farm. The site is an alluvial deposit, meaning the crystals have eroded out ...

Sometimes George Harlow looks more like a medieval magician than the curator of gems and minerals at the American Museum of Natural History. Sweeping an ultraviolet light wand over a box of rocks in a ...

Corundum, the crystalline form of aluminium oxide, is the host mineral for the gem varieties ruby and sapphire. Characterization of corundum deposits involves geological classification, mineralogical ...

The Perseverance rover has found precious stones inside Martian pebbles. These gem grains are made of a substance called corundum, which is also known as ruby or sapphire depending on the traces of ...

A 'selfie' taken by the Curiosity rover taken on the Martian surface. Courtesy of NASA/JPL-Caltech/MSS Courtesy of NASA/JPL-Caltech/MSS For decades, Mars has surprised scientists with evidence of ...

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 ...