Answer:
Gold and silver
Explanation:
The term, Columbian Exchange is named after Christopher Columbus. During the Columbian Exchange, Europeans and American Indians established trading connections where goods and natural minerals exchanged. Native Americans offered gold and silver in trade to Europeans during the Columbian Exchange. Gold and silver considered being the most valuable item in Europe as it generates wealth and prosperity. The presence of gold and silver in abundance allowed the Columbian Exchange to become more intense and harmful to the natives.