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Vent: My first try at acid testing a mystery rock went sideways
I picked up this smooth, dark gray stone from a creek bed near my uncle's place in Kentucky. It was heavy for its size and had a weird, waxy look. I was sure it was some kind of chert or flint, so I got a small bottle of vinegar to do a basic acid test at home. I put a drop on it, expecting nothing, but it fizzed like crazy! Not a little, but a full-on sizzle for a good five seconds. I was totally wrong, it's definitely a carbonate rock, maybe limestone or dolomite. I learned that looks can be super deceiving, and even a simple kitchen test can prove your guess wrong in a big way. Has anyone else had a rock completely surprise them with a simple test?
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paigec1413d ago
Honestly that vinegar test can be tricky. A strong fizz doesn't always mean limestone, some rocks just have a carbonate coating from the creek. You might still have chert under that reaction.
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kim.emma13d ago
That's a fair point from @paigec14, but a strong fizz usually points to the whole rock being reactive. Scratching past the surface to test the fresh material underneath is the real key.
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