Nevada.
Minnesota.
Arkansas is the US state out of which come the most diamonds. The United States just doesn't have the "right geology" to have diamonds as a natural resource. Diamonds usually come from or appear near (having washed out of) kimberlite pipes. The geology of the US is broad and breathtaking, but does not include much in the way of these unique geologic structures.
Delaware.
Georgia.
The US
Nevada.
Michigan
Ohio
Texas
Kentucky.
Kentucky produces the most gold in the Untied States.
South Carolina
California!
Minnesota.
Michigan
MICHIGAN