Thread: Anybody have any ideas as to what this might be?

Can you give me further info on testing? I would like to discover what the heck this is for sure. I figure it is at least 6 Mohs if it cuts hardened steel, right? What sort of acid would I need? I have some Bar Keeper's Friend - would the amount of oxalic acid in that do anything to help ID? I don't think I have anything else besides vinegar ATM.

Try to light it on fire and see what happens.

Uh. Yeah. Anyway, tried the vinegar after reading that it should bubble if it's limestone - no dice, the vinegar just sat on top of the stone like water. Same with oxalic acid paste.

Yes vinegar will bubble on limestone. Use a steel test too.

Oxalic acid is mostly used to clean iron stains off. In the lab you need some HCL-dilute is enough. The vinegar should give some reaction though if it's limestone. For hardness You can use a chunk of quartz if you have it to test at level 7 or some feldspar for level 6. Apatite for level 5 Fluorite for 4 and calcite for 3.

Don't have any of those, but I can probably get some muriatic acid from where I used to work - think they have a jug. I've also read that some limestones need to be crushed to show much reactivity, so I'll try that too. Would granite give me any idea of hardness? I have some of that around.

Originally Posted by eKretz

Don't have any of those, but I can probably get some muriatic acid from where I used to work - think they have a jug. I've also read that some limestones need to be crushed to show much reactivity, so I'll try that too. Would granite give me any idea of hardness? I have some of that around.

Probably not because granite is typically comprised of quartz, feldspar and mica. They sell inexpensive kits for the mohs hardness scale. Educational stores have them. I'll bet toys are us has it too.