Shoutout to the park ranger who saw me trying to identify a rock with a magnet

I was at Joshua Tree last month, holding a magnet to a piece of basalt like it was a magic wand. The ranger walked over and said, 'That only works for magnetite, friend.' I'd been doing it for years on every dark rock I found. Turns out I was basically checking if my car keys were metal. Anyone else have a basic field test they were using totally wrong?

3 comments

3 Comments

lee.diana2mo ago

Wait, doesn't a magnet work on any magnetic rock though, not just magnetite? Like some types of basalt can have magnetic bits in it.

leohart2mo ago

Right, that's a good point.

dylanward1mo ago

Oh man, I've actually been there! I tried using a regular fridge magnet on some random rocks I found hiking, and it didn't really stick to most of them. But then I got one of those strong neodymium magnets, and that was a TOTAL game changer. It pulled magnetic bits out of all sorts of rocks that looked totally normal on the outside. So yeah, a basic magnet will only work on the most magnetic stuff, but a stronger one will grab onto those tiny bits in basalt and other rocks too.