What is the relationship between 'gold mine' and 'gold' in the context of the input sentence.
Options: product/material produced, member of, legal form, location of formation

The mine began production in 2013, and is the only primary gold mine in the world with annual production of more than one million ounces of gold (100% basis), at all-in sustaining costs below $700 per ounce.
product/material produced