Mine, Mining

MINE, MINING. Excavation for minerals began long before historic times, when Neolithic miners obtained flint (q.v.) for use in weapons and implements and gathered salt which played an important part in determining the course of trade in the ancient world. Initially both minerals would have been scraped from the surface, or, in the case of flint, removed from a bank of chalk (chalkstone, q.v.). Subsequently the quarrying and underground extraction of flint would have been stimulated by the discovery that freshly extracted flint was more easily chipped than surface stones as it contained some ground water. Also mined by Neolithic man was red and yellow ochre (iron, q.v.) for use as pigments.

The mining methods used by Neolithic man were little improved upon in many of the metal mines, worked by slaves, that supplied mineral wealth to the empires of Egypt, Assyria, Greece and Rome. However, the range of materials mined increased. The metals of the pre-Christian era—copper, gold, iron, lead, silver, tin (q.v.) and to a lesser extent, mercury and zinc—were all mined, in their native state in the case of copper, gold and silver, or as other ores, except in the case of gold. Early mining of other minerals took place in the ancient Near E, particularly for gems and ornamental material. The ancient Egyptians sank hundreds of shafts in the search for emeralds on the coast of the Red Sea, but turquoise was prob. the first material used in jewelry to be mined extensively. This was carried out on the Sinai Peninsula, an operation that meant people living in places that otherwise would be uninhabited and building roads or tracks that otherwise would not have been made. However, these mining tracks were of considerable use during the Exodus from Egypt of the children of Israel (cf. Exod 15:22-16:1). See Metals and Metallurgy.

The wealth and exploits of the various empires and states of the ancient Near E were closely linked to the exploitation of metallic ore deposits by mining. Gold (q.v.), which is widely distributed and found in the relics of man in many countries, was abundant and mined to a considerable extent in Egypt, and formed the basis of this nation’s wealth during the height of its powers. The rise of Israel to a nation was related to the annexing of Edom, with its copper and iron deposits, by David (2 Sam 8:14), and their exploitation both during his reign and the subsequent reign of Solomon (1 Kings 4-10). The history and power of the city-state of Athens is closely linked with the silver mines of Laurion and of their exploitation. In the 4th cent. b.c. the wealth and exploits of Philip of Macedon, and then of his son Alexander the Great, were linked with the gold mining of the Mount Pangeus district near Philippi, where the output was so high that the Greeks believed that the gold regenerated itself as it was gathered.

The mining of copper in Cyprus made the island a prized possession successively of the Egyptians, Assyrians, Phoenicians, Greeks, Persians and Romans. Even the mining of tin in Cornwall, England, had a considerable bearing on the history of the ancient Near E because of the trade by the Phoenicians in this metal needed for making bronze. The iron of Anatolia and Armenia was closely linked with the successive power of the Hitties (c. 1400-1200 b.c.) and then the Philistines (q.v. iron).

The methods and conditions of mining in the pre-Christian era are illustrated by mining for gold in ancient Egypt, for turquoise and copper in the Sinai Peninsula and for silver in Greece. (Fig. 1.)

Gold in ancient Egypt. Alluvial mining by washing river sands and gravels produced the earliest gold before 4000 b.c. This placer gold then was traced back to the source veins which were mined, particularly in the Northern Sudan (the ancient Nubia, a name thought to have been derived from the Egyp. nub, meaning gold). There were several producing districts in the desert between the 18th and 23rd latitudes and between the Nile and the Red Sea. Gold also came from the Coptos region to the N, also between the Nile and the Red Sea.

Underground mining was carried out on a series of adit levels and using slave labor. The harder rock was cracked by making wood fires against the rock face and then throwing water on the hot rocks. Hammers were used to reduce the size of the pieces before being carried out of the mines to be further reduced in size in stone mortars and then in stone hand mills. The rock dust was then washed on a sloping board, the sand being washed off and the heavy gold flakes remaining.

Turquoise and copper on the Sinai Peninsula. Turquoise (q.v.) of a period earlier than 3400 b.c. is known from Egypt. Whether it was mined by Egyptians on the Sinai Peninsula, or obtained by barter from the Bedouins of that region is not known. However, references to mining at the northeastern end of the Red Sea are among the earliest inscrs. in Egypt and pictorial records of mining covering the period 3200 to 1150 b.c. were found on sandstone cliffs in the Wadi Maghara, on the Sinai Peninsula. Here turquoise and malachite (q.v.), both minerals of copper, were mined, initially for decorative purposes and jewelry and, in the case of malachite, as a green face paint and as a paint for the eyes to lessen the glare of sunlight.

The early workings were mainly for turquoise, and this was extracted with the aid of flint tools, the nodules of turquoise being separated from the encasing friable sandstone by hammering. When it was discovered, prob. by accident, that malachite would smelt to copper in a charcoal (camp) fire, this mineral was mined and copper wedges and chisels made for use in the mining of turquoise. Later malachite was mined to obtain copper to send back to the main part of Egypt. A room-and-pillar method of mining was used with individual chambers up to twenty-four ft. long and six ft. across.

These copper deposits are not of the type associated with ores of tin, and this may explain why Egypt lagged behind other countries in the use of bronze (q.v.), the coppertin alloy.

Silver in Greece. The silver mines of Laurion, about twenty-five m. S of Athens, prob. were being worked by 1000 b.c. and they provided much of the wealth of the city-state of Athens some five hundred years later. The ore mined was mainly lead sulphide (galena) which contained 30 to 300 ounces of silver per ton of lead, the silver being extracted by metallurgical processes (metals and metallurgy q.v.). There are associated minerals of iron and zinc. Most of the ore occurs in a limestone near its contact with a schist, a foliated rock of metamorphic origin. The earliest mining was done where the ore body cropped out at the surface and was oxidized. Here there was native silver as well as carbonates of lead, zinc (brass q.v.) and iron. Cuts or passages were made in the hillside and these were the laurai (lanes) which gave Laurion its name.

Ore at deeper levels was of sulphide minerals, mainly the argentiferous galena, and occurring mainly as tabular masses, up to thirty-five ft. thick, at the limestone-schist contact. More than two thousand shafts were sunk, the deepest being to 386 ft. below the surface. The main shafts were six ft. by four ft., with footholds to assist climbing, but the underground passages were generally only two to three ft. high and across. The mining was carried out by slaves in chains, using the pillar-and-stall type of stope, with patches of poor ore being left as pillars. In smaller stopes dry stone constructions supported overhanging rock. Timber was not commonly used. Because the passages were small, ventilation was poor and mining by fire-setting followed by quenching with water could not have been used. However, fires were used to assist the movement of air in the shafts.

Each slave, who had a lamp made of baked clay containing enough oil to burn ten hours, broke about twenty-five tons of rock a month using a hammer, chisel, pick, and shovel the metallic parts of which were of hammered and tempered iron. The broken ore and waste were passed from man to man in panniers of hide or grass, then taken to the surface. Here it was crushed in stone mortars and iron pestles, then sieved on to large (seventy ft. by forty ft.) washing tables constructed of masonry faced with mortar. The flow of water carried away the lighter gangue and left behind the ore which was then gathered, smelted and treated using various other metallurgical processes (metals and metallurgy q.v.).

Bibliography T. A. Rickard, Man and Metals. A History of Mining in Relation to the Development of Civilization. Vols. I and II (1932).