FMF - Friends of Minerals Forum, discussion and message board

[SlowFrog]

Hi! I’m in the UK but my dad was Irish. He brought back lots of quartz rocks from his dad’s birthplace after visiting. I broke up one of the smaller rocks because I was curious about how it might look inside. To my surprise, it had way more variation than I was expecting so I have uploaded some pics to try and find what else is going on within them! I really don’t know much at al about this subject matter but I’d definitely go away and learn more with some information to go on/work with.

Thank you in advance and I hope you find it as interesting as I have!

[SlowFrog]

After washing a couple of the above fragments, I noticed some silvery deposits. Any idea what they are?

[Pete Richards]

Most likely the silver granules are pyrite, a form of iron sulfide. The brown stuff is probably a mixture of several iron oxides, which may have resulted at least in part from the weathering of pyrite. Most of the rest appears to just be quartz.

[SlowFrog]

Thank you, Pete! That's exactly the sort of info I was hoping for.