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Moissanite (/ ˈ m ɔɪ s ə ˌ n aɪ t /) [5] is naturally occurring silicon carbide and its various crystalline polymorphs.It has the chemical formula SiC and is a rare mineral, discovered by the French chemist Henri Moissan in 1893.
In 1893, Moissan began studying fragments of a meteorite found in Meteor Crater near Diablo Canyon in Arizona. In these fragments he discovered minute quantities of a new mineral and, after extensive research, Moissan concluded that this mineral was made of silicon carbide. In 1905, this mineral was named moissanite, in his honor.
Reconstruction of Ötzi's copper axe (c. 3300 BCE). The Copper Age, also called the Eneolithic or the Chalcolithic Age, has been traditionally understood as a transitional period between the Neolithic and the Bronze Age, in which a gradual introduction of the metal (native copper) took place, while stone was still the main resource utilized.
Gold, silver and copper were the first to be used by ancient humans. Gold and copper are both found in their 'native' state in nature, and were thus the first to be exploited as they did not need to be smelted from their ores. They could be hammered into sheets or decorative shapes.
[citation needed] Starting around 5,500 BCE, early smiths began to re-shape native metals of copper and gold, without the use of fire and by using tools and weapons. The heating of copper and its shaping with hammers began around 5,000 BCE. [citation needed] Melting and casting started around 4,000 BCE.
Earliest humans Charcoal and soot were known to the earliest humans, with the oldest known charcoal paintings dating to about 28000 years ago, e.g. Gabarnmung in Australia. [1] [2] The earliest known industrial use of charcoal was for the reduction of copper, zinc, and tin ores in the manufacture of bronze, by the Egyptians and Sumerians. [3]
Archaeologists in Spain have unearthed a 2,100-year-old bronze hand that both astounded and puzzled experts. At the foot of a castle on Mount Irulegi, the invading ancient Roman army attacked and ...
The earliest gold artifacts were discovered at the site of Wadi Qana in the Levant. [13] Silver is estimated to have been discovered in Asia Minor shortly after copper and gold. [14] There is evidence that iron was known from before 5000 BC. [15] The oldest known iron objects used by humans are some beads of meteoric iron, made in Egypt in ...