Worldwide, the Bronze Age generally followed the Neolithic period, but in some parts of the world, a Copper Age served as a transition from the Neolithic to the Bronze Age.

The start of the Copper Age ( apprx.

Reconstruction of a Copper Age walled city, Los Millares, Iberia

The Chalcolithic ( khalkos " copper " + lithos " stone ") period or Copper Age, also known as the Eneolithic / Æneolithic ( from Latin aeneus " of bronze "), is a phase of the Bronze Age in which the addition of tin to copper to form bronze during smelting remained yet unknown by the metallurgists of the times.

The Copper Age was originally defined as a transition between the Neolithic and the Bronze Age.

In 1881 John Evans recognizing that the use of copper often preceded the use of bronze distinguished between a transitional Copper Age and the Bronze Age proper.

Subsequently the British used either Evans ' Copper Age or the Eneo-or Aeneo-lithic, a translation of Chierici's eneo-litica.

After several years a number of complainants appeared in the literature that Eneolithic seemed to the untrained eye to be produced from e-neolithic, " outside the Neolithic ," clearly not a definitive characterization of the Copper Age.

Today Copper Age, Eneolithic and Chalcolithic are used synonymously to mean Evans ' original definition of Copper Age.

The literature of European archaeology, in general, avoids the use of ' chalcolithic ' ( the term ' Copper Age ' is preferred ), whereas Middle Eastern archaeologists regularly use it.

The Copper Age in the Middle East and the Caucasus began in the late 5th millennium BC and lasted for about a millennium before it gave rise to the Early Bronze Age.

The transition from the European Copper Age to Bronze Age Europe occurs about the same time, between the late 5th and the late 3rd millennia BC.

Inorganic compounds show rich variety: A: Diborane features Three-center two-electron bond | unusual bonding B: Caesium chloride has an archetypal crystal structure C: Cyclopentadienyliron dicarbonyl dimer | Fp < sub > 2 </ sub > is an Organometallic chemistry | organometallic complex D: Polydimethylsiloxane | Silicone's uses range from breast implant s to Silly Putty E: Grubbs ' catalyst won the Nobel Prize in Chemistry | 2005 Nobel Prize for Robert H. Grubbs | its discoverer F: Zeolite s find extensive use as molecular sieve s G: Copper ( II ) acetate surprised Theoretical chemistry | theoreticians with its diamagnetism

The shared features between the Eyak language found around the Copper River delta and Tongass Tlingit near the Portland Canal are all the more striking for the distances that separate them, both geographic and linguistic.

Copper cladding enables architects to incorporate visually desirable features into building design.

The Deluxe features 2 Seth Lover-designed Wide Range humbuckers with " Cunife " ( Copper / Nickel / Ferrite ) rod magnets in the place of pole-pieces.

The Long Walk had been laid out by King Charles II and the planting of its trees completed by William of Orange in the 1680s, with double rows of elms which lasted until World War II, but the Georges extended it and built numerous features and monuments, such as the Copper Horse ( depicting George III ) and the Obelisk ( in honour of William, Duke of Cumberland ).

Copper bronze smelting system processes mature, decoration features prominent, revealing a very strong culture color.

The boundary between the Copper and Bronze Ages is indistinct, since alloys sputtered in and out of use due to the erratic supply of tin.

Microliths were also used from the Neolithic on arrows, although a decline in this use coincided with the appearance of bifacial or " leafed " arrowheads that became widespread in the Calcolithic period, or Copper Age ( that is, stone arrowheads were increasingly made by a different technique during this later period ).

* Copper was in use, both as tools and weapons.

As a standard underlying medium it uses optical fiber, although it can use copper cable, in which case it may be referred to as CDDI ( Copper Distributed Data Interface ).

Copper was already in use in telegraph cables and this is the very best conductor available short of using silver.

Copper sulfate and Bordeaux mixture ( copper sulfate plus lime ), approved for organic use in various jurisdictions, can be more environmentally problematic than some synthetic fungicides dissallowed in organic farming Similar concerns apply to copper hydroxide.

In 1899, the U. S. Army built a pack trail for summer use between the port of Valdez and Eagle, which passed through the Copper River Valley.

Copper has been in use at least 10, 000 years, but more than 95 % of all copper ever mined and smelted has been extracted since 1900.

According to the International Resource Panel's Metal Stocks in Society report, the global per capita stock of Copper in use in society is 35 – 55 kg.

Copper pesticides remain in use in rare instances on organic crops.

* Copper was in use, both as tools and weapons

On October 9, 2008, Serbian archaeologists at Pločnik found a copper axe believed to be 500 – 800 years older than the actual beginning of the Copper Age, suggesting that the human use of metal is older than believed.

Copper can be used everywhere except North America, where its use is illegal because of the formation of dioxin.

Copper ax blades and knives provide the first evidence of metal use in Switzerland.

* Miles Glacier Bridge ( built 1910 ), also known as the Million Dollar Bridge, converted from railroad to motor vehicle use and located at the northern end of the unfinished Copper River Highway near Cordova Alaska.

Copper indicates broader trade relations in the southern Maya lowlands, and as a reflection of technological change, the history of metal artifact use at Lamanai is an invaluable element in the reconstruction of Postclassic and early historical dynamics.

Copper objects such as bells, rings, and tweezers not only had great economic value but were also highly charged symbolic objects whose sounds and colors made them particularly important for use in ritual performances and as ornaments reflecting social status.

Copper azole preservative ( denoted as CA-B and CA-C under American Wood Protection Association / AWPA standards ) is a major copper based wood preservative that has come into wide use in Canada, the USA, Europe, Japan and Australia following restrictions on CCA.

This was the result of the announcement that the Copper River and Northwestern Railway ( CR & NW ) was going to use the town's location as its access to the Pacific Ocean and the Bering River coal fields.

Copper cathodes produced using this method are also described as electrolytic copper.

See also: Antimicrobial properties of copper, Copper alloys in aquaculture

The Old Copper Complex, located in present-day Michigan and Wisconsin in the United States, used copper for tools, weapons, and other implements.

Copper plated bullets are lead bullets that are electroplated with a copper jacket.

In 1955, he joined the recently formed Copper Office ( Departamento del Cobre, now CODELCO ), where he worked until 1959 as a research analyst in the copper industry.

The transition from the Stone Age to the Bronze Age was a period during which modern people could smelt copper, but did not yet manufacture bronze, a time known as the Copper Age, or more technically the Chalcolithic, " copper-stone " age.

The first evidence of human metallurgy dates to between the 5th and 6th millennium BCE in the archaeological sites of Majdanpek, Yarmovac and Pločnik ( a copper axe from 5500 BCE belonging to the Vincha culture, though not conventionally considered part of the Chalcolithic or " Copper Age ", this provides the earliest known example of copper metallurgy.

The current clad version is two layers of cupronickel ( 75 % Copper, 25 % Nickel ) on a core of pure copper giving a total composition of 8. 33 % Ni with the remainder Cu, weighs 5. 670 grams ( 0. 2000 avoirdupois oz, 0. 1823 troy oz ), diameter 0. 955 inches ( 24. 26 mm ), width 1. 75 millimeters ( 0. 069 in ) with a reeded edge.

The metals suitable for wire, possessing almost equal ductility, are platinum, silver, iron, copper, aluminium and gold ; and it is only from these and certain of their alloys with other metals, principally brass and bronze, that wire is prepared ( For a detailed discussion on copper wire, see main article: Copper wire and cable.

Copper wires are also plated with other metals, such as tin, nickel, and silver to handle different temperatures, provide lubrication, provide easier stripping of rubber from copper.

( For further information about copper magnet wire, see: Copper wire and cable # Magnet wire ( Winding wire ).

Copper mining was intensified, and copper crosses were probably used as a currency.

Copper output has increased steadily since 2004, due to higher copper prices and the opening of new mines.

He prepared a lavish inauguration for himself in Brussels, where he gave the people copper coins ( leading to his first nickname, the Copper King ).

* Resolution Copper, a copper mining project in near Superior, Arizona

Copper thermite, using copper oxide, is used for creating electric joints in a process called cadwelding:

Copper thermite can be prepared using either copper ( I ) oxide ( red ) or copper ( II ) oxide ( black ).