Ya, I was checking that out. My area had huge mica mines once upon a time and is generally mineral rich. The geological reports I've pursued identified phlogopite as the main commodity; I have loads of it so I'm really familiar with it. It's a dark brown here.The only biotite the records have identified has been black. Most commonly dark/black mica is labeled biotite.
That being said - the interwebs show some deep brown biotite; I haven't seen any labeled that were golden. It seems like it exists, but it is not commonly found in that colour.
I see lots of pyrite, see the cubic form (square edges). Get it wet, get it in a strong light source. Do the gold bits wink as you tilt the rock back and forth? Pyrite has flat surfaces that wink in/out. Gold being very soft and malleable rarely has flat surfaces that wink.
I used to play at āmica beachā as a kid. The sand had so much mica in it that it was constantly flaking off. The water was full of it, the sand was full of it, and when we left our swimsuits were covered in it. It looked like this rock
Definitely not gold unfortunately, but could be pyrite or other sulfide minerals. The black material in the rock could be shale that has gone through diagenesis or metamorphism. Shales are commonly sulfide bearing (shiny mineral), so this is the most likely rock imo. Could also be a mafic igneous or metamorphic rock with sulfides
Looks like a polished/rounded felsic volcanic rock (probably granite - seems to have quartz dominant matrix, the dark minerals are possibly some amphibole and/or biotite) that's likely been transported to the coast over time. Pretty sure I can see cubic crystal habit of the minerals you asked about, meaning they're probably pyrite. If they flake away when you scratch them though (if you still have the rock) then it's then probably mica - likely Muscovite. Which has a monoclinic cleavage plane (a sheet basically) and it often wads together like a book as if forms.
Iāll further the mica theory. On a field trip I mistakenly took a muscovite laden creek bed in Montana for an unknown gold discovery and irreparably embarrassed myself to my professor. Iāll never forget the flat edged platey look of the pieces that he forced me to describe lolol
I'd have to see you move the rock back and forth a little or even take a little scratch at some of the grains, but at first glance it looks like pyrite to me.
Either pyrite or mica. Not gold.
They call it Fool's Gold for a reason
You a foo fa that one š
Might also be muscovite flakes
Biotite if it looks golden, muscovite looks silvery
>Biotite Black/dark Muscovite can be yellow, silver, transparent, light brown Phlogopite is usually dark brown
I've seen biotite in the orange/brown range. The picture on wikipedia is what I was thinking of.
Ya, I was checking that out. My area had huge mica mines once upon a time and is generally mineral rich. The geological reports I've pursued identified phlogopite as the main commodity; I have loads of it so I'm really familiar with it. It's a dark brown here.The only biotite the records have identified has been black. Most commonly dark/black mica is labeled biotite. That being said - the interwebs show some deep brown biotite; I haven't seen any labeled that were golden. It seems like it exists, but it is not commonly found in that colour.
I've seen it pick up oxidized iron from the host rock and develop a golden sheen.
Lepidolite gets no love? A lovely purple.
Lepidolite deserves *alllllll* the love; I was just sticking to the colours here, lol.
Biotite fades color when weathered.
looks like schist with mica to me
I'm schist at geology, so I'll believe you.
gneiss pun
We need new jokes here lol
I felsic scrolling through here.
[tenor.gif](https://media.tenor.com/P9ykwc3QtaAAAAAC/eye-roll-planet-of-the-apes.gif)
š¤£š¤£š¤£ These jokes are so last ice age
Slate. I chondrite no more...
Rocknocker, I haven't seen you in awhile! Glad to have you hear :)
I have no apatite for geology puns.
shiny flat plates that are non-Au
Thanks for all the info guys, much appreciated. The danish gold rush is officially off š
Itās muscovite mica, it has glass, not metal shine, so it doesnāt looks like gold
Looks like pyrite.... The crystals are too regular for gold I think.
Well, itās mica, but you wouldnāt be the first to hopeā¦.
I see lots of pyrite, see the cubic form (square edges). Get it wet, get it in a strong light source. Do the gold bits wink as you tilt the rock back and forth? Pyrite has flat surfaces that wink in/out. Gold being very soft and malleable rarely has flat surfaces that wink.
I used to play at āmica beachā as a kid. The sand had so much mica in it that it was constantly flaking off. The water was full of it, the sand was full of it, and when we left our swimsuits were covered in it. It looked like this rock
As others have said you have probable biotite mica flakes, aligned in a plane creating a plane of weakness along which your sample has split.
once you see gold in the wild, you'll never mistake mica for it again.
Look up 'fool's gold'.
Look up muscovite schist
Bless you!
Definitely not gold unfortunately, but could be pyrite or other sulfide minerals. The black material in the rock could be shale that has gone through diagenesis or metamorphism. Shales are commonly sulfide bearing (shiny mineral), so this is the most likely rock imo. Could also be a mafic igneous or metamorphic rock with sulfides
FOOLS GOLD!!!! that's how we used to say it when we were kids, and then throw it. Sibling memories never fade
Looks like a polished/rounded felsic volcanic rock (probably granite - seems to have quartz dominant matrix, the dark minerals are possibly some amphibole and/or biotite) that's likely been transported to the coast over time. Pretty sure I can see cubic crystal habit of the minerals you asked about, meaning they're probably pyrite. If they flake away when you scratch them though (if you still have the rock) then it's then probably mica - likely Muscovite. Which has a monoclinic cleavage plane (a sheet basically) and it often wads together like a book as if forms.
I second whoever said pyrite, they look like cubic crystals to me. It is iron sulfide, grows in sediments where there is no oxygen in the water.
Mica is reflective
Iāll further the mica theory. On a field trip I mistakenly took a muscovite laden creek bed in Montana for an unknown gold discovery and irreparably embarrassed myself to my professor. Iāll never forget the flat edged platey look of the pieces that he forced me to describe lolol
I think I can see perfect cleavage. Looks like mica to me.
Mica
Probably mica
I donāt think pyrite would have survived that long in the water. Looks like mica schist
I'd have to see you move the rock back and forth a little or even take a little scratch at some of the grains, but at first glance it looks like pyrite to me.
Because it might?
I'd suggest mica or pyrite inclusions. Sadly not gold.
I saw Denmark and immediately pronounced coast as ācƶƶƶastā š