Vent: I tried using a potato to clean a really stubborn calcite sample

I was cleaning a big calcite cluster from a dig in Kentucky, and it had this awful, greasy clay stain stuck in all the cracks. Nothing was working, not even a soft brush and soapy water. I remembered my grandpa saying something about using a potato to clean old coins, so I figured, why not? I cut a raw potato in half, rubbed the wet side all over the calcite, and let it sit for about ten minutes. When I rinsed it off, most of that nasty stain just washed away. I think the oxalic acid in the potato juice did the trick. It felt pretty silly, standing there rubbing a rock with a potato, but it actually worked. Has anyone else ever used a weird kitchen item to clean a mineral find?

2 comments

2 Comments

luna_white9326d ago

Potato trick is a classic. Vinegar works on some stuff too.

the_julia26d ago

Okay but isn't that oxalic acid a bit harsh for calcite long term? I'd be worried about etching the surface. @luna_white93 mentioned vinegar, which is also acidic and could do the same damage. Sometimes the old kitchen tricks are a little too strong for softer minerals.