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The Qijia culture (c. 2500–1900) of Qinghai, Gansu, and western Shaanxi produced copper and bronze utilitarian items and gold, copper, and bronze ornaments. The earliest metalworks in this region are found at a Majiayao site at Linjia, Dongxiang, Gansu. [7] "Their dates range from 2900 to 1600 BCE.
There is evidence that gold and meteoric iron (but not iron smelting) were the only metals used by humans before copper. [3] The history of copper metallurgy is thought to have followed the following sequence: 1) cold working of native copper, 2) annealing, 3) smelting, and 4) the lost wax method.
West Mexican smiths worked primarily in copper during the initial period, with some low-arsenic alloys, as well as occasional employment of silver and gold. Lost-wax cast bells were introduced from lower Central America and Colombia during this phase, along with several classes of cold-worked ornaments and hand tools, such as needles and tweezers.
Illustration of stepwise bronze casting by the lost-wax method. Lost-wax casting – also called investment casting, precision casting, or cire perdue (French: [siʁ pɛʁdy]; borrowed from French) [1] – is the process by which a duplicate sculpture (often a metal, such as silver, gold, brass, or bronze) is cast from an original sculpture.
Excavations revealed more than 700 high quality artifacts of copper, bronze and iron, as well as about 165,000 glass, carnelian and stone beads, pottery, textiles and ivory beads, cups, and horns. The bronzes include numerous ritual vessels, pendants, crowns, breastplates, staff ornaments, swords, and fly-whisk handles.
These are mostly gold or a gold alloy (with copper or silver) and have been found to be largely cold hammered and sand-polished alluvial nuggets, although a few items seem to have been produced by lost wax casting. It is presumed that at least some of these items were acquired by trade from Colombia. [39]
The team found Corinthian alabaster, Attic vases, and locally-made ritual jugs. They also uncovered treasure of a shinier kind: gold, silver, coral, and amber jewelry, amulets from the East, and ...
Candle moulding machine in Indonesia circa 1920. Candle making was developed independently in a number of countries around the world. [1]Candles were primarily made from tallow and beeswax in Europe from the Roman period until the modern era, when spermaceti (from sperm whales) was used in the 18th and 19th centuries, [2] and purified animal fats and paraffin wax since the 19th century. [1]