Shoutout to the time I mixed up shale and slate in the field...

I was collecting samples for a class project and grabbed a piece of what I thought was slate... It felt right and had that smooth cleavage, so I didn't think twice... Back in the lab, when I tried to split it, it just crumbled into layers... Turns out it was shale that had been compacted but not fully metamorphosed... I lost a good sample and had to go back out to find the real thing... It taught me to pay more attention to the subtle differences in rock types... Now I make sure to carry a hand lens to avoid such mix-ups.