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Spent a whole weekend trying to figure out a weird rock in my yard
I found this dark, heavy rock with little green crystals in it while digging a hole for a new bush. I thought it was basalt at first, but it didn't look quite right. I spent maybe 15 hours over two days looking at my old field guide and checking online pictures. Turns out it's gabbro, which is like basalt's slower-cooling cousin. I felt pretty silly for not seeing it sooner. Has anyone else mixed up two rocks that look really similar?
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jennyfisher7mo ago
My first year in geology club, I spent three weeks convinced a piece of granite was granodiorite. The grain size gets everyone. For gabbro and basalt, you really need to get a hand lens on those green crystals, check if they're olivine. A cheap 10x loupe saves so much time guessing.
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stella1117mo ago
That whole rock mix-up thing reminds me of when my brother tried to identify a weird mineral he found. He was so sure it was one thing, but jennyfisher is right about needing a closer look. He ended up borrowing a magnifying glass from a neighbor, which helped a little, but it was still a guess. He finally took it to a local rock shop and the guy there knew right away. Sometimes you just need a second pair of eyes on it, even if it feels like giving up.
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