This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Jöns Jacob Berzelius isolated silicon in 1824 by reducing potassium fluorosilicate with molten potassium and washing the brown powder that resulted. He had no way of knowing that the element he had just purified would, roughly a century and a half later, give its name to a stretch of land south of San Francisco Bay and, through it, to the modern technology economy.
The route from Berzelius's powder to Silicon Valley runs through a specific chemical accident that turned out to be extraordinarily useful. When silicon is exposed to air below about 900 degrees Celsius, it forms a thin, continuous surface layer of silicon dioxide that protects the material beneath from further oxidation, so the reaction is self limiting rather than self sustaining. That protective layer is what let the Fairchild physicist Jean Hoerni build the 1959 planar process: leaving the oxide in place on a silicon wafer to protect the sensitive junctions underneath, then opening and closing precise windows in it for each diffusion step, the technique that made repeatable, mass produced transistor manufacturing possible.
The economic scale that followed is difficult to overstate from where Berzelius stood. Roughly four fifths of the world's elemental silicon production today goes not into electronics at all but into ferrosilicon alloys for steelmaking, an industrial use with no glamour attached to it. It is the much smaller remainder, refined further into semiconductor grade material, that becomes the transistors, integrated circuits and solar cells that a nineteenth century chemist studying an obscure element inside a Swedish laboratory could not have anticipated naming a valley, let alone an age.