Jolyon Ralph created a guide to the rocks and minerals of Minecraft: "Have you ever wondered how similar the Minecraft resources are to rocks and minerals in the real world? Let's find out!"
"Wait," I hear you shout, "Dirt isn't a rock!" Well, actually, it kinda is. Except we should probably call it 'soil' rather than 'dirt' because 'soil' sounds just a tiny bit more scientific, and we like that. To be more strict, we're talking about sediment rather than rock.
It's wonderful. I'd love to see this guide, or something similar, turned into a little geology book with old-timey watercolor paintings…