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Metals and metal working had been known to the people of modern Italy since the Bronze Age. By 86 BC, Rome had already expanded to control an immense expanse of the Mediterranean. This included nine provinces radiating from Italy to its islands, Spain, Macedonia, Africa, Asia Minor, Syria and Greece, and by the end of the Emperor Constantine’s reign, the Roman Empire had grown further to encompass parts of Britain, Egypt, all of modern Germany west of the Rhine, Dacia, Noricum, Judea, Armenia, Illyria and Thrace (Shepard 1993). As the empire grew, so did its need for metals. Central Italy itself was not rich in metal ores, leading to necessary trade networks in order to meet the demand for metal from the Republic. Early Italians had some access to metals in the northern regions of the peninsula in Tuscany and Cisalpine Gaul, as well as the islands Elba and Sardinia. With the conquest of Etruria in 275 BC and the subsequent acquisitions due to the Punic Wars, Rome had the ability to stretch further into Transalpine Gaul and Iberia, both areas rich in minerals. At the height of the Roman Empire, Rome exploited mineral resources from Tingitana in north western Africa to Egypt, Arabia to North Armenia, Galatia to Germania, and Britannia to Iberia, encompassing all of the Mediterranean coast. Britannia, Iberia, Dacia, and Noricum were of special significance, as they were very rich in deposits and became major sites of resource exploitation(Shepard 1993). . There is evidence that after the middle years of the Empire there was a sudden and steep decline in mineral extraction. This was mirrored in other trades and industries. One of the most important Roman sources of information is the Naturalis Historia of Pliny the Elder who died in the eruption of Mount Vesuvius in 79 AD. Several books (XXXIII-XXXVII) of his encyclopedia cover metals and metal ores, their occurrence, importance and development. == Types of metal used == Many of the first metal artifacts that archaeologists have identified have been tools or weapons, as well as objects used as ornaments such as jewellery. These early metal objects were made of the softer metals; copper, gold, and lead in particular, as the metals either as native metal or by thermal extraction from minerals, and softened by minimal heat (Craddock, 1995). While technology did advance to the point of creating surprisingly pure copper, most ancient metals are in fact alloys, the most important being bronze, an alloy of copper and tin. Alloys are mixtures of different metals created either by smelting or by forging. It is important to note that an ore does not necessarily constitute an alloy; ore is a collection of minerals and alloyed metals. As metallurgical technology developed (hammering, melting, smelting, roasting, cupellation, moulding, smithing, etc.), more metals were intentionally included in the metallurgical repertoire. By the height of the Roman Empire, metals in use included: Gold, Silver, Copper, Tin, Lead, Zinc, Iron, Mercury, Arsenic, Antimony (Healy 1978). As in the Bronze Age, metals were used based on many physical properties: aesthetics, hardness, colour, taste/smell (for cooking wares), timbre (instruments), aversion to corrosion, weight, and countless other factors. Many alloys were also possible, and were intentionally made in order to change the properties of the metal e.g. the alloy of predominately tin with lead would harden the soft tin, to create pewter, which would prove its utility as cooking and tableware. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Roman metallurgy」の詳細全文を読む スポンサード リンク
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