Lapidaryforum.net
Let's Rock => Identifications of Materials => Topic started by: Jw on April 20, 2022, 01:29:55 PM
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The picture is of a rock that someone wants me to carve into a heart and I’m just curious as to what kind of rock it is since they don’t know it was bought in Virginia any ideas on what it could be are greatly appreciated
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It looks like chert with lots of internal stress.
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That doesn’t sound favorable but thanks for the possible Id
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chets can be fabulos rough. Looks like lots of inclusions which is common and not a structural problem. Good luck.
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This description is slightly inaccurate after seeing the rock in person it is more purple-ish
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Does it appear translucent if you shine light into it or through it?
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Nope entirely opaque
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My vote goes to anhydrite. How hard is it?
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Not super hard but harder than a steel knife blade
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Check if it reacts with acid. Anhydrite is calcium sulphate and should fizzy up nice. If not, nix that theory!
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Does the acid matter ?
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It's a good way to eliminate or affirm certain minerals. I was just suggesting a simple home test you could do if you wanted to figure it out that bad. Quartz won't react to acid.
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I meant like specific type and does it have to be a very Lowe ph or can a milder acid like vinegar do the trick
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I use white vinegar for any table top testing. It's not as exciting, but you'll see results regardless. Sorry for the mix-up!
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The picture is of a rock that someone wants me to carve into a heart and I’m just curious as to what kind of rock it is since they don’t know it was bought in Virginia any ideas on what it could be are greatly appreciated
Better lighting can help, but looks like it could be Burro Creek purple agate.
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Check if it reacts with acid. Anhydrite is calcium sulphate and should fizzy up nice. If not, nix that theory!
Anhydrite is dehydrated calcium sulfate, but it does not fizz with acid. Carbonates fizz with acid, such as calcium carbonate. This is why acids are used to differentiate between anhydrite stones such as angelite and calcium carbonate stones such as calcite, travertine and marble.
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Thank you, VegasJames!