Can we talk about how slate and shale are basically twins?

I picked up what I thought was slate on a trail last week. My geology buddy insists it's shale. They both split into flat pieces and have that gray color. I read online that slate is metamorphic and shale is sedimentary, but who can tell just by looking? It's frustrating because I want to learn, but the details feel overwhelming. Maybe I need a better guide or something.

3 comments

3 Comments

val8221mo ago

Actually, calling them twins is a big stretch. Slate forms under heat and pressure, making it way harder and less crumbly than shale. Once you learn to spot that difference, it becomes pretty clear they're not the same.

emmao551mo ago

Imagine using shale for a roof, good luck.

hannaho521mo agoMost Upvoted

Wait, are we talking about roofing? Because shale is a terrible roofing material, it just flakes apart. But old slate roofs can last over a hundred years if they're done right. The big difference is in how they're split and installed. A good roofer knows how to nail a slate so it doesn't crack in the next freeze.