The foreign trade network was where Great Zimbabwe thrived. Trade with Swahili city-states, East Africa and Europeans is what made Great Zimbabwe rich. Due to poor agriculture, the gold trade had become extremely important among African nations. The king mined and traded gold and ivory with the Swahili coast of East Africa and with Europeans. The Mutapas were major exporters of gold. They mined the northern areas of a coral reef that runs northeast-southwest along the catchments of all Zimbabwe's rivers to coastal ports. The gold was mined by the farmers but had to be given to the king as tribute. Gold was the main basis of the wealth of the Zimbabwean economy because it was highly sought after by Arab ports. The ivory trade was also booming as it had great monetary value as it lasted longer than gold. Each madzimbahwe generated its own surplus which was used for exchange. Caches of imported objects such as Indian glass beads, Chinese celadon plates, and silk were found by archaeologists in the abandoned cities of Great Zimbabwe. Dominance over gold sources in the interior gave Great Zimbabwe a great commercial advantage over its rivals which developed with Kilwa and Sofala along the coast which developed alongside Arab centers through the gold trade. The balance between exports and imports with Africa could not be achieved easily. What African nations considered valuable and what foreigners considered valuable were two very different things. The value of gold was strong in African cultures, but objects such as pottery and beads traded by the Arabs had a greater value due to their rarity, while for the Arabs gold was much more important than the goods that… of paper... trade influenced the steady decline of Great Zimbabwe. More than 20 million ounces of gold were extracted from the earth and used for trade. The combination of falling world gold prices and the depletion of the gold supply resulted in the collapse of Great Zimbabwe's economy which left the nation unable to import food to replenish its dwindling crops as the monoculture. of Great Zimbabwe can be explained due to trade, environmental conditions, disease or even overpopulation. Trade can be seen as the main contributor as the change in the value of gold influenced the outcome of the survival of Great Zimbabwe the most. If the great gold trading network had continued and if the value and export of gold to Africa had remained at optimal levels, the people of Great Zimbabwe would have survived and the city would never have abandoned.