Final answer:
Gold and copper were the two resources mined that provided Ghana with its wealth, contributing significantly to its economic prosperity from ancient times up to the eleventh century as recorded by Islamic observers.
Step-by-step explanation:
The two resources mined that provided Ghana's wealth were gold and copper. From ancient times, gold has been mined in the region, with methods such as panning for gold in streams and at the base of waterfalls being employed traditionally. Copper was another valuable commodity, with the king levying a custom duty on it. Even during the eleventh century, Islamic eyewitnesses like al-Hamdani and al-Bakri emphasized the immense wealth derived from Ghana's gold mines. The extraction of these resources played a critical role in the economic prosperity of Ghana.