Thanks, 2guys, for setting the record straight on Mesa Minerals having a source of ore themselves.
On grades, etc., you'll have to read up from the various reports, such as those sent to AMY by Norm Tribe and Norm Chow in the past, and available at AMY's website, as well as materials published by Mesa Minerals and others involved in the Mn industry at different levels of product, about all the different kinds of geology involved.
High grade does not necessarily or even often equate with low costs or quick recovery or processing times.
One of the reasons Artillery Peak looked/looks so attractive is the "friable" nature of its deposits and what we have been told is easily recoverable Mn down to the 2% level or even lower, whereas the hard, carbonate ore used by China and evidently by Mesa Minerals is of the type that requires lots of crushing and roasting and concomitant impurities and ecological toxicity....
Looking at different resources is, therefore, always going to be something of an "apples and oranges" comparison, IMO.