Tin extraction and use can be dated to the beginnings of the Bronze Age around 3000 BC, when it was observed that copper objects formed of polymetallic ores with different metal contents had different physical properties.- Strato of Lampsacus (Wikipedia)
Strato of Lampsacus (/ˈstreɪtoʊ/; Greek: Στράτων ὁ Λαμψακηνός, translit. Strátōn ho Lampsakēnós, c. 335 – c. 269 BCE) was a Peripatetic philosopher, and the third director (scholarch) of the Lyceum after the death of Theophrastus. He devoted himself especially to the study of natural science, and increased the naturalistic elements in Aristotle’s thought to such an extent, that he denied the need for an active god to construct the universe, preferring to place the government of the universe in the unconscious force of nature alone.