"...used X-ray fluorescence (XRF) analysis to identify an unusual copper alloy stain on the stone which might have been left by some sort of copper or brass object in the distant past." by T.K. Randall via unexplained-mysteries image credit: CC Aaron Bradley A historic stone that has been used in the coronation of monarches for centuries has yielded some surprising secrets. This oblong block of red sandstone might not appear to be anything special, but for over 800 years the kings and queens of Scotland (and more recently those of Great Britain) have been coronated with the stone - also known as the Stone of Scone - playing an important role in the ceremony. It will be used again when King Charles III is coronated on May 6th of this year. The stone itself is usually kept under lock and key and away from the eyes of the public, which means that actually studying it in any detail has long been something of a challenge for historians. Now, though, scientists with Historic Environment