Responsible Sourcing of Raw Materials

Intent: "To protect ecosystems, respect cultural and community values, and improve land use through responsible sourcing of raw materials used for building products." The requirement for mined or quarried materials in this credit requests a signed letter from the owner of a manufacturing/extraction company that declares a “public commitment to responsible mining.” I am concerned that since "responsible mining" certification does not yet exist, such a letter won't carry much weight. Since non-mined/bio-based materials ARE required to meet 3rd party certification requirements, shouldn't mined/quarried be encouraged to do so as well? Thoughts?