Forbes
By David Bressan
January 7, 2023
A research team using new methods to analyze data from NASA’s Curiosity, a rover operating on Mars since 2012, was able to independently verify that fractures in the bedrock contained opal, on Earth a gemstone formed by the alteration of silica by water. Unlike common crystals, opal is an amorphous mineral consisting of layers of microscopic silica-spherules with water filling the gaps between them. Light is scattered along the surface of the spherules, giving common opal colors ranging from white to yellow to red. The most valuable “noble opal” display a glittering array of rainbow colors.