Mineral wealth has little value in underdeveloped countries for a plethora of reasons, the most notable being lack of infrastructure and the dependency on the primary sector.
Mineral wealth has very little value in underdeveloped countries because many LDCs (less developed countries) lack the infrastructure needed to import and export minerals that could possibly boost the economic state. This lack of transportation reduces profitability significantly.
Mineral wealth also has little value because many underdeveloped countries rely heavily on agriculture. For this reason, much industrialization and mining is neglected because it isn’t needed.
A lot of underdeveloped countries don’t value mineral wealth because the countries don’t have the needs to keep it around (transportation, markets, infrastructure in general).