τοπάζιον

Topaz derives from Greek τοπάζιον (topázion), the name of a specific gemstone, itself derived from the name of an island — Topazios or Topazos — mentioned by ancient geographers as a source of yellow-green gems in the Red Sea. The island's name may come from Greek τοπάζειν (topázein, 'to guess, to surmise'), reflecting the island's legendary difficulty to locate in the fog and waves of the Red Sea: sailors had to guess where it was. Alternatively, the name may preserve an older, non-Greek word for the island whose etymology is lost. Pliny the Elder located the island's gem-mines definitively and described the stones as yellow-green, translucent, and prized. The problem is that what the Greeks and Romans called topazion was almost certainly not what modern mineralogy calls topaz.

The identification controversy is genuine and unresolved: the ancient topazion described by Pliny was probably peridot (magnesium iron silicate, colored yellow-green by iron), not modern topaz (aluminum silicate fluoride, which in its pure form is colorless and becomes blue, yellow, or orange through impurities and irradiation). The confusion arose because ancient gem classification was based on color and appearance rather than chemical composition, and yellow-green stones from multiple mineral families were grouped together. Modern topaz and ancient topazion share a color range but not a chemical identity. The word traveled through Latin topazus and Old French topace into English 'topaz,' carrying with it an identification problem that ancient users never knew they had.

The genuine mineral we now call topaz was known in medieval Europe but called by various names depending on its color. Yellow topaz was often called chrysolite or chrysoberyl (from Greek chrysos, gold); blue topaz was called aquamarine; colorless topaz was called 'Saxon diamond.' The reclassification of these varieties as forms of the same mineral — aluminum silicate with fluorine, the second-hardest naturally occurring mineral after corundum — was a project of eighteenth and nineteenth-century mineralogy. By the time the chemical identity of topaz was established, the name had been attached to a mineral family that ancient writers had not clearly distinguished from its neighbors.

Brazilian topaz deposits, discovered in the eighteenth century, produced spectacular specimens of golden imperial topaz — a variety whose saturated yellow-orange color was so vivid that it seemed to contain light. Brazilian topaz quickly became among the most coveted yellow gemstones in the world, and the name topaz was fixed on this mineral at the expense of the ancient identification with the Red Sea island's peridot. The island that gave the stone its name — foggy, hard to find, perhaps half-legendary — has been entirely lost to the stone it named. Topazios exists now only in etymology; the stone has moved to a continent the ancient Greeks never knew.