Metals of antiquity

The metals of antiquity are the seven metals which humans had identified and found use for in prehistoric times. These elements, gold, silver, copper, tin, lead, iron, and mercury, are the metals from which the modern world was forged. Until the discovery of arsenic in the 13th century, these were the only known elemental metals, compared to the 86 known today.

Characteristics

Melting point

The metals of antiquity generally have low melting points, with iron being the obvious exception.

• Mercury melts at −38.829 °C (-37.89 °F)^[1] (being liquid at room temperature).
• Tin melts at 231 °C (449 °F)^[2]
• Lead melts at 327 °C (621 °F)^[3]
• Silver at 961 °C (1763 °F)^[4]
• Gold at 1064 °C (1947 °F)^[5]
• Copper at 1084 °C (1984 °F)^[6]
• Iron is the outlier at 1538 °C (2800 °F),^[7] making it essentially impossible to melt in antiquity.

Extraction

While all but tin and lead occur natively, only gold and silver are by any means commonly found as the native metal. However, no temperature higher than 900 °C (easily reachable with charcoal and bellows) was required to extract these metals from their ores.

• Gold and silver occur frequently in their native form
• Mercury compounds are reduced to elemental mercury by simple heat (500 °C).
• Tin and iron occur as oxides and can be reduced with carbon monoxide (produced by, for example, burning charcoal) at 900 °C.
• Copper and lead can be roasted to produce the oxides, then reduced with carbon monoxide at 900 °C.

Rarity

While widely known during antiquity, these metals are by no means common. Of the 78 elements occurring naturally in the earth's crust in quantity (all the elements until bismuth, with the exceptions of the noble gases, technetium, and promethium, but also including thorium and uranium), with oxygen and silicon being the first two:

• Iron is the 4th (4.1% by mass)
• Copper is next at 26th (50ppm)
• Lead is 37th (14ppm)
• Tin is 49th (2.2ppm)
• Silver is 65th (70ppb)
• Mercury is 66th (50ppb)
• Gold is the 72nd (1.1ppb)

Yet all were known and available in tangible quantities in ancient times.

See also

• Timeline of chemical element discoveries

Symbolism

Each of the metals was associated with one of the seven then-known celestial bodies, and one of the seven days of the week.^[8]

References

• "History of Metals". 
• Nick Kollerstrom. "The Metal-Planet Affinities - The Sevenfold Pattern". Retrieved 2011-02-17. 

http://www.webelements.com/ cited from these sources:

• A.M. James and M.P. Lord in Macmillan's Chemical and Physical Data, Macmillan, London, UK, 1992.
• G.W.C. Kaye and T.H. Laby in Tables of physical and chemical constants, Longman, London, UK, 15th edition, 1993.