Articles of pre-columbian jewelry, C. 250 BC AD 1500, made in Ecuador by the native Indians, especially, so far as is known today, along the northern coast, in the Esmeraldas region, near La Tolita, that extends also into Colombia; but some gold finds have also been made in the southern highlands.
The pieces were made mainly of gold or tumbaga flat sheet metal cut out and decorated in «repousse» work or cast by the «cire perdure» process.
Articles included some exceptionally tiny gold nose rings and labrets; circular copper ornaments (sometimes called ‘gongs’, but possibly breast ornaments), embossed with a human or puma face; minute coiled springs worn as ear ornaments; and studs of gold, emerald or turquoise worn in holes pierced in the cheek or lip. Some articles were covered with gold plating and some were made of an alloy of platinum and gold produced by sintering.
It is a process of causing a powdered or granular material to become a solid coherent mass by heating without completely melting it.
Some Ecuadorian jewelry was made of an alloy of gold and platinum produced by heating grains of platinum and gold dust and then hammering them to form a mass; the Indians of Ecuador had learned that they could not produce heat sufficient to work the local platinum and developed the process of sintering.
The secret was lost until it was rediscovered in the 19th century.