Tiny geodes found, lake/mchenry county Illinois.. What are they, Crystals minerals Options

[GRenee1980]

Hello all! Former Colorado resident now in Illinois. I live on the border of lake/mchenry counties in Illinois, about 10-15 miles from Wisconsin border. I've recently found several tiny geodes in a nearby farm field. I am curious as to what they are. Tiny/ nickel sized geodes with white druzy crystals. Unsure if Quartz or calcite. I haven't tried to dig any.. All those found have been lying on surface. Any thoughts or opinions? I've scoured the Internet and cannot find anything. I know that western IL and southwest Iowa are keokuk geodes.. But I'm 3-4 hours away in Northeast Illinois. Photos included

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[MikeS]

Welcome to the forums GRenee1980!

Your geodes look like Calcite to me. Nearby limestone would indicate Calcite should be around. I have a sure fire test for you. Rinse a lesser piece in water then let it dry. Put a few drops of vinegar on it. If the vinegar starts to fizz or make bubbles then you have Calcite (calcium carbonate). If you can't get a bubbling reaction then it is likely Chalcedony(Quartz).

[GRenee1980]

Hi Mike! Thanks for the welcome and suggestion.
I tried a scratch test. I also tried your vinegar suggestion but that's inconclusive.. I got no reaction, but then I tried ur suggestion on 2 separate calcite specimens I have, one pink calcite and one Brazilian. Neither specimen bubbled or fizzed. I even chipped a tiny bit off each of those n crushed up. Maybe my vinegar is no good??? Sure smells potent. Lol.
Still seeking guidance and suggestions.
Best regards,
Gretchen

[MikeS]

Hi Mike! Thanks for the welcome and suggestion.
I tried a scratch test. I also tried your vinegar suggestion but that's inconclusive.. I got no reaction, but then I tried ur suggestion on 2 separate calcite specimens I have, one pink calcite and one Brazilian. Neither specimen bubbled or fizzed. I even chipped a tiny bit off each of those n crushed up. Maybe my vinegar is no good??? Sure smells potent. Lol.
Still seeking guidance and suggestions.
Best regards,
Gretchen

Hmmm. I am not sure if vinegar looses it's acidity if old but that is a possibility. The solid pieces may bubble real slow but if the vinegar is acidic and it's Calcite you should get some reaction, especially powdered. I get some amount of bubble reaction on every form of Calcium Carbonate I have tried. Calcite, Aragonite, Limestone, Marble, Chalk, Montmorillonite all bubble. I use white vinegar 5% acidity. Hope this helps Gretchen. The only other home test I know won't help much cause the specific gravity of quartz and calcite are so close. Quartz= 2.65 Calcite= 2.71

[GRenee1980]

Mike! Thx, you rock! Ok.. Bad joke. I'll buy fresh white vin tomorrow!
I can't get enough of this site, reading so many posts and threads. I've always loved crystals, minerals, and surrounding activities. Wanted to be a geologist as a kid! Study, prospect and discover... Somehow it I wound up an info security auditor. I miss the mountains and the outdoors!
I'll update you on findings once I have retested with diff/new vinegar...
Best Regards!!!
Gretchen- aka GG