Earth Sciences 1089F/G Lecture Notes - Lecture 8: Galena, Arsenic, Steelmaking
7 Oct 2016
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Document Summary
Heavy metal thunder: early history of metal use in human culture. Humans relied on materials such as obsidian, chert, and quartzite for manufacture of tools. Tool evolution: simple tools with cutting edge, tools with more refined edge, tools with maximized cutting surface, sophisticated spear points. Late stone age: early uses of native metals. Humans discovered native gold was soft and malleable, and could be fashioned into objects of beauty. Nuggets of gold were commonly used for this. Objects made from native gold were extremely valuable. Resistance of gold to corrosion & oxidation = even more valuable. Second metal used by humans (earliest use was 6,000bc) Native copper (pure form), which occasionally occurs in large masses was. Cold-worked to make delicate objects hooks & needles (difficult to make from stone and bone) Only nobility could afford objects made rom metal. Major limitation of cold-worked copper: it"s brittleness, it"s softness.
