Born of Fire and Fury, I Now Radiate a Cool Blue Beauty

THE PERIODIC FURY of Vesuvius has mostly brought fear and destruction to its surrounding slopes, but it also delivered me — a gem collector’s favorite — to the surface. First described in 1807, I was named after one of the French founders of the science of gemology. Today, I can be found in a handful of locations, from the Canary Islands to upstate New York, although the best specimens – which display a transparent electric blue – come from the Eifel Mountains in Germany. While my fragility limits my use as a gemstone, in (extremely rare) large and clean sizes I can command prices that rival those of the most illustrious gems.

Who am I?