![]() After a thorough investigation that lasted three years and included more than fifty tests, Müller determined the specific gravity of the mineral and noted that when heated, the new metal gives off a white smoke with a radish-like odor that it imparts a red color to sulfuric acid and that when this solution is diluted with water, it has a black precipitate. The following year, he reported that this was erroneous and that the ore contained mostly gold and an unknown metal very similar to antimony. In 1782 Franz-Joseph Müller von Reichenstein, who was then serving as the Austrian chief inspector of mines in Transylvania, concluded that the ore did not contain antimony but was bismuth sulfide. Tellurium (Latin tellus meaning "earth") was discovered in the 18th century in a gold ore from the mines in Kleinschlatten (today Zlatna), near today's city of Alba Iulia, Romania. All other known metals (iron, copper, silver, gold, zinc, mercury, tin, lead and bismuth) had no recorded discoverers. Cobalt became the first metal to be discovered since the pre-historical period. He showed that compounds of cobalt metal were the source of the blue color in glass, which previously had been attributed to the bismuth found with cobalt. Swedish chemist Georg Brandt (1694–1768) is credited with discovering cobalt circa 1735, showing it to be a previously unknown element, distinct from bismuth and other traditional metals. ![]() Because the primary ores of cobalt always contain arsenic, smelting the ore oxidized the arsenic into the highly toxic and volatile arsenic oxide, adding to the notoriety of the ore. The first attempts to smelt those ores for copper or silver failed, yielding simply powder (cobalt(II) oxide) instead. The word cobalt is derived from the German kobalt, from kobold meaning "goblin", a superstitious term used for the ore of cobalt by miners. Read moreĬobalt has been used to color glass since the Bronze Age. ![]() Scheffer described platinum as being less pliable than gold, but with similar resistance to corrosion. In 1752, Henrik Scheffer published a detailed scientific description of the metal, which he referred to as "white gold", including an account of how he succeeded in fusing platinum ore with the aid of arsenic. After publishing the report in 1748, Ulloa did not continue to investigate the new metal. Ulloa also anticipated the discovery of platinum mines. His historical account of the expedition included a description of platinum as being neither separable nor calcinable. Antonio de Ulloa returned to Spain and established the first mineralogy lab in Spain and was the first to systematically study platinum, which was in 1748. Ulloa and Juan found mines with the whitish metal nuggets and took them home to Spain. In 1735, Antonio de Ulloa and Jorge Juan y Santacilia saw Native Americans mining platinum while the Spaniards were travelling through Colombia and Peru for eight years. ![]() The first European reference to platinum appears in 1557 in the writings of the Italian humanist Julius Caesar Scaliger as a description of an unknown noble metal found between Darién and Mexico, "which no fire nor any Spanish artifice has yet been able to liquefy". Archaeologists have discovered traces of platinum in the gold used in ancient Egyptian burials as early as 1200 BCE. ![]()
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