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Pre-columbian Metals
Silver • Copper • Bronze • Iron |
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Silver |
Deer vessel, 14th–15th century; Chimú
North Coast
Silver; H. 5 in. (12.7 cm)
The Michael C. Rockefeller Memorial Collection
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Precious metals
had a special status in Ancient American civilizations. As materials,
silver and gold were symbols of power and prestige and also held symbolic
and religious significance. Objects of silver and gold were worn exclusively
by the elite, and expressed social status and political authority in life
and death when they were placed as offerings in tombs with the deceased. The
title of the exhibition derives from an Inka invocation chanted by tillers
working the fields: "The sun rains gold, the moon rains silver."
While today gold commands more
attention than silver because it is more highly valued, silver was to the
ancients equally cherished and revered. When the Spaniards arrived in South
America in the 16th century, they discovered a vast area on the Pacific
side, stretching from Ecuador in the north to central Chile in the south,
ruled by the Inka. They reported that all the gold and silver in the land
was the property of the supreme ruler of the Inka and that those two metals
were associated with celestial deities. The warm, reflective glow of gold
symbolized the sun, a male deity; the soft, cool sheen of silver symbolized
the moon, a female deity and source of life-giving waters.
From a modest beginning in the
late first millennium B.C. when silver first appeared in small personal
adornments, it was exploited to its fullest during the 12th through 15th
century, when the Lords of the Chimú Kingdom ruled over the northern part of
the Peruvian coast. At that time silver was used for objects of all kinds,
from grand items of jewelry such as earflares and necklace beads, to disks
and vessels both large and small, to sheathing elements for sizeable works
in materials such as wood. Necessitating greater technical ability and
knowledge than the working of gold—which exists as a metallic element in
nature—silver must be smelted and refined before it can be made into
objects.
Vessel in the form of an outstretched
figure, 14th–15th century; Chimú North Coast - Silver, gold alloy; 4 1/2
x 8 in. (11.4 x 20.3 cm) Metropolitan Museum |
Panpiper vessel, 14th–15th century;
Chimú
North Coast
Silver, malachite inlay; H. 8 1/4 in. (20.9 cm)
The Michael C. Rockefeller Memorial Collection
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Double-walled beaker with repoussé
decoration, 14th–15th century; Lambayeque (Sicán)/Chimú
North Coast
Silver; H. 6 in. (15.2 cm), Diam. 5 1/2 in. (14 cm)
Denver Art Museum |
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Copper Alloy |
A pectoral of tumbaga, of the Quimbaya
culture. 300-1600 AD.
Click here for more about Tumbaga and Gold » |
Tumbaga is an alloy composed
mostly of gold and copper. It has a significantly lower melting point than
gold or copper alone. It is harder than copper, but maintains malleability
after being pounded.
Tumbaga can be treated with a simple acid, like citric acid, to dissolve
copper off the surface. What remains is a shiny layer of nearly pure gold on
top of a harder, more durable copper-gold alloy sheet. This process is
referred to as depletion gilding.
Tumbaga was widely used by the
pre-Columbian cultures of central America to make religious objects. Like
most gold alloys, tumbaga was versatile and could be cast, drawn, hammered,
gilded, soldered, welded, plated, hardened, annealed, polished, engraved,
embossed, and inlaid.
The proportion of gold to copper in artifacts varies wildly; items have been
found with as much as 97% gold while others instead contain 97% copper.
Some tumbaga has also been found
to be composed of metals besides gold and copper, up to 18% of the total
mass of the tumbaga. |
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Precolumbian Bronze |
Argentinian Belen Culture Bronze disc |
It is a common misconception that pre-Colombian
Americas lacked bronze and thus were not able to deploy hardened copper
alloys. Copper alloys are reported as ‘guanín’ by Colombus. This
misconception may well arise because tin, the common component of Eurasian
bronze (although common in Bolivia), is rare in the Caribbean basin.
However, copper, iron, manganese, nickel, chromium, and cobalt and zinc,
copper and manganese mixed into a matrix of iron sulfides and other metal
sulfides gold, cobalt, nickel, etc are readily available, often glittering
in such minerals as pyrite, fools gold, the brassy golden yellow cubanite,
marcasite etc on the surfaces of the common place once submerged karst rock
formations of these islands.
Thus guanín could well be a manganese bronze. Today US “gold dollars” are
made of a probably similar alloy 88.5 % copper, 6% zinc, 3.5% manganese, and
2% nickel [2]. However, it should be noted that nickel has a melting
temperature well above that produced by even a bellowed kiln (and bellows
were probably first employed some time after 300 BC in China) so it would be
rather unlikely that guanin would have contained nickle.
Thus Columbus’s report of metal axes in lands and seas of the Caribbean
although viewed skeptically by some cannot be readily dismissed [3]. In this
cited article these authors attribute this bronze to the Mayans. One might
keep in mind that the Mayans were in trading contact with the Taínos who
used the word guanín to describe the copper alloys they used for ornamental
and religious purposes, and in addition there were readily available
deposits of the necessary ores (see above) in the Major Antilles. The
existence of pre-colombian metal tools in the Americas is finally considered
"fact" [4], the question is which ethnicities, nations or civilizations had
these objects. Thus classification of Taíno technological progress as merely
Neolithic may well be an understatement awaiting archeological resolution of
Taíno use of guanín alloy tools. |
Argentinian
Santa Maria
Bronze Disc |
Argentinian Aguada Bronze Disc/Plaque |
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Iron In Ancient America |
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Although a few ancient objects
made of meteoric iron have been discovered in America as well as in Eurasia,
no objects made of smelted iron have ever been found in America
However, this page has been
added to address the issue of Iron making in Ancient America.
While to technology existed to
make Iron in the Americas (particularly in the Andean civilizations), the
knowledge did not, since no artifacts of manufactured iron, nor the tools,
have been found.
Ancient America did produce
alloys of:
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Iron is a chemical element. It is a strong,
hard, heavy gray metal. It is found in meteorites. Iron is also found
combined in many mineral compounds in the earth's crust. Iron rusts easily
and can be magnetized and is strongly attracted to magnets. It is used to
make many things such as gates and railings. Iron is also used to make
steel, an even harder and tougher metal compound. Steel is formed by
treating molten (melted) iron with intense heat and mixing it (alloying)
with carbon. Steel is used to make machines, cars, tools, knives, and many
other things.
The exact date at which people first
discovered how to smelt iron ore and produce usable metal in the "Old World"
is not known. Archaeologists have found early iron tools that were used in
Egypt from about 3000 BCE. Iron objects of ornamentation were used even
earlier. By about 1000 BC, the ancient Greeks are known to have used heat
treatment techniques to harden their iron weaponry. These historical iron
alloys, all iron alloys produced until about the fourteenth century ad, were
forms of wrought iron.
Wrought iron was made by first heating a
mass of iron ore and charcoal in a forge or furnace using a forced draft of
air. This generated enough heat to reduce the iron ore to a hot, glowing,
spongy mass of metallic iron filled with slag materials. The slag contained
metallic impurities and charcoal ash. This iron sponge was then removed from
the furnace and while still glowing hot, it was pounded with heavy sledges
to separate the slag impurities and to weld and form the purer mass of iron.
The iron produced in this way almost always contained slag particles and
other impurities, but occasionally this technique of small batch iron making
yielded a true steel product rather than wrought iron. These early iron
makers also learned to make steel by reheating wrought iron and charcoal in
clay boxes for several days, until the iron absorbed enough carbon to become
a true hardened steel.
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