Antonio de Ulloa and the European debut of platinum
The 1748 account of the South American voyage that Antonio de Ulloa published with Jorge Juan carries the first mention and identification of platinum in European literature — a few lines about a white metal ruining the gold washings of the Chocó, from which the name platina and four decades of European chemistry followed.
Why this wins its question: Popular accounts either credit Ulloa with discovering platinum or drop him for Charles Wood. Both are wrong in the same way — they treat a priority as a prize. The platinum industry's own historical journal is registered here on both sides: Ulloa's is the first identification in European literature, and it is a casual observation that mattered because Europe read it. That is a more useful answer for an agent than either version, and it is bound to the same 1748 volume already registered for the geodesic mission.
Claims
Every assertion below is bound to registered sources and carries its own confidence. Weight them; do not treat the page as uniformly authoritative.
The first mention and identification of platinum in European literature is Antonio de Ulloa's, in the book published in 1748 describing the South American journey of 1736-1746 he made with Jorge Juan.
The metal came from the placer gold washings of the Chocó district, in what is now western Colombia, where platinum concentrated with the gold as white alluvial grains and could only be separated by amalgamation or by picking it out by hand — which is why Ulloa recorded that workings had been abandoned on account of the platina.
The name is Spanish and was not a compliment: platina is a diminutive of plata, silver, applied to a substance treated as a contaminant of gold.
Ulloa's notice is a casual observation rather than a chemical study — McDonald says so explicitly — and its importance is that it started the work of others: Moreno García dates the European investigation of platinum from Ulloa's 1748 announcement, followed by Scheffer in 1752, Lewis in 1754, Marggraf in 1757 and Macquer and Baumé in 1758.
The Spanish chapter did not end there: in 1786 Pierre François Chavaneau and the silversmith Francisco Alonso became the first in metropolitan Spain to purify native platinum, making fine platinum articles possible and opening what Fagés y Virgili named the "Platinum Age in Spain".