There were seven known metals until the 1200s CE: gold, silver, copper, tin, lead, iron, and mercury. These were the metals that built humanity’s first civilizations. (For those who point out the Bronze Age from about 3300 BCE to 1200 BCE, bronze is a mix of copper and tin.)
Arsenic was discovered in the 1200s, antimony in the 1400s, and things just took off from there. Today there are 86 known metals.
