Victor Goldschmidt, the father of modern geochemistry, was born on this day in 1888. A Swiss-born Norwegian chemist, Goldschmidt was fascinated by the elements, their origins, and their relationships in nature. With the new tool of x-ray crystallography, he and his co-workers studied 200 compounds made of 75 elements and constructed the first tables of ionic and atomic radii. Goldschmidt showed that a compound's hardness was related to the distances between atoms in its crystal structure. Goldschmidt also pioneered spectrographic methods for rapidly discerning minute amounts of elements and determined that Earth's crust is made up primarily of oxygen anions--90% of its volume--along with silicon or metal cations.
[Source: Roy Porter, Ed., The Biographical Dictionary of Scientists (Oxford University Press, ed. 2, 1994).]