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Microsoft develops ultra durable glass plates that can store several TBs of data for 10000 years
(unlocked.microsoft.com)
This is a most excellent place for technology news and articles.
They're being so vague with the numbers that I really doubt how mature any of this is. Given some of the examples (photos, music, War & Peace) I'm guessing 3TB or so, but it's a fluff article, so who knows.