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CATEGORY: geology
DEFINITION: A process in metallurgy, the separation of gold or silver from impurities by melting the impure metal in a cupel (crucible) and then directing a blast of hot air on it in a special furnace. The impurities, including lead, copper, tin, and other unwanted metals, are oxidized and partly vaporized and partly absorbed into the pores of the cupel. It is used to obtain silver by separating it from the lead with which it is naturally associated in argentiferous lead ores, or to obtain gold from the naturally occurring alloy of argentiferous gold (electrum).
DEFINITION: The ancient capital of King Archelaus of Macedonia at the end of the 5th century BC (until 168 BC) and birthplace of Alexander the Great. It is in northern Greece, northwest of Thessaloníki. The city flourished under Philip II, but, after the defeat of the last Macedonian king by the Romans (168 BC), it became a small provincial town. Excavations have revealed houses with colonnaded courts and rooms with mosaic floors made with small natural pebbles of various colors, dating from the late 4th century BC. The town had a rectangular grid plan; under the streets are terra-cotta pipes for distributing fresh water.

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