I know some of it (a) is quartz but what is it combined with? Seems rough. In pic B the stone is mostly white and very hard but I don't think it is quartz. Could be wrong. Look forward to your input. I found it near an old limestone quarry btw. Near a river.

Edited August 22Aug 22 by fudgetusk

Looks very much like a flint nodule: a form of chert associated with chalk and limestones.

You're right, it's chiefly cryptocrystalline quartz (the crystals are too small to make out even with a hand lens), and your's looks to have a coating rich in haematite which produces the reddish browns. The dark green speckles may well be chlorite with the rest of the coating various other clay minerals and probably a bit of calcite.

Pure chert shows white, so the central mass in pic B appears particularly quartzy to me. Why do you think it isn't?

Thank you, scholar. Some new words to discover there.

Something to do with limestone eh?

Hey this will tickle you...check out this mark on the stone.

What does it look like? It foxed me for years. Then I read a book of symbols yesterday. It's a rare alchemical symbol for Calx. Which as you know means 'Limestone.'

Ain't that funny?

Now I'm off to Gullible.com to find out what this stone does to my chakras.

Edited August 26Aug 26 by fudgetusk