THE RIDDLE OF THE BLUE CRYSTAL: A DIAMOND’S ENIGMATIC INCLUSION IS AN INTRIGUING MESSENGER FROM ONE OF EARTH’S LAST FRONTIERS

A blue inclusion in a diamond macle continues to be the subject of intense investigation to determine why such a small crystal has such extraordinary color. Over a four year period, some of the most technologically advanced instrumentation in the world has yielded volumes of data and a conclusion that this pleochroic crystal is olivine, though as yet no conclusive reason for its anomalous color. Nonetheless, the high degree of scrutiny to which this diamond and its inclusions have been subjected is in itself a remarkable story and provides insights into a world deep within the Earth – arguably one of its last frontiers and one which is otherwise inaccessible.

Along with their significance to understanding geological processes in the mantle and the formation of diamonds, an overview is presented of experiments conducted at Northwestern University’s mineral physics laboratory, Cornell University’s mineral physics laboratory, the Bayerisches Geoinstitut at the University of Bayreuth, the Department of Terrestrial Magnetism at the Carnegie Institution of Washington, the Gemological Institute of America at Carlsbad, CA, the American Museum of Natural History, as well as, extensive studies at three synchrotron sources: the Advanced Photon Source (APS) at Argonne National Laboratory; the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory and the Cornell High Energy Synchrotron Source (CHESS).

The riddle of the blue inclusion is the subject of fascinating research; theories for its blue color and intended directions for further investigation are also addressed.