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I think the modern run came in blue and white boxes. I have a couple old NOS Lily White Washitas that are pretty close to pure white, they're just not super common because the stones were so good...

As far as I'm aware, the only testing done at all is density/specific gravity. And that isn't tested on every stone by a long shot. (This according to Dan's website IIRC).

Personally I think old vs. new doesn't make any difference - all the stones are the same age in reality since they formed at the same time. In point of fact, it could be said that the earliest mined...