Why Are So Many Early CC-Morgans So Blackened And Other Early Mintmarks Blast White?

The Carson City coins were exposed to fumes from coal and wood fires for heat, kerosene lamps for light and much harsher conditions in manufacture and transportation. The Carson City mint was also quite remote with rough 'roads' used to move the coins as it was located near the silver supply causing more Bag Marks, exposure to dust, moisture and maybe even rain from time to time. I'm sure that impurities in the alloys used for the coins also has a lot to do with the dark coloration of these coins.

I'm sure the other mint locations had some of the same conditions to deal with, it just seems to me that the CC mint was more of a Wild West type of operation.

This is just my thinking from what I've read over the years. I could be way off.

BU CC's were mostly in bags until Nixon freed them; silver dips take a lot of credit for blast white coins: I remember a dealer's case at an old Bay State show, 1980s?, in which every Morgan and Peace dollar were dipped-that was the "thing to do"