score:4
[OP here. Found the answer and will share for future generations with the same question.]
In the book Historical Statistics of the United States, Colonial Times to 1970 published by the United States Census Bureau relevant information can be found in chapter M on minerals. In particular, page 582 and following pages contain information on historic prices for a comprehensive list of minerals including gold, silver, iron, copper, clay, cement, lime and many more. Historical prices start from 1870.
Upvote:5
US Geological Survey has some publications which may be of interest to you.
Here for example is the report on Copper. It lists prices in cents per pound every year from 1850 to 1998.
Here is the same report for Aluminum. This one has many gaps tho, and only includes three prices before 1895.
Edit: This publication appears to roll up all the other data into one document. There are extensive references cited which you may find useful as well.