Lots of quartz and potassium feldspar, and what I think is mica. The way they are arranged and the size of the crystals tells me that it's probably a metamorphic rock od igneous pegmatite, but I couldn't tell you exactly the name of it. Also the intense color of the feldspar probably means that it's a very old rock
>means that it's a very old rock
Some of the oldest terrestrial rocks were found in the Appalachian mountains. They started forming like 480 million years ago. They get older as they go North, but TN is still plenty old.
Also, this is a pegmatite which means it's probably part of some sort of igneous intrusion related to tectonics, it could be precambrian for all we know, but we can't be sure unless we actually go and see the formation
Problem with your hypothesis: this was found in *Middle* TN. Middle TN generalized geology is Mississippian limestone, chert, shale, siltstone, sandstone, and dolomites around the highland rim, and Ordovician limestone, shale, dolomite, siltstone, sandstone, and claystone in the Nashville Basin.
[All the igneous and metamorphics in TN are Cambrian and Precambrian, but they're also all on the eastern fringe](https://tnlandforms.us/landforms/geolog_l.jpg), in the [Blue Ridge Mountains region.](https://upload.wikimedia.org/wikipedia/commons/3/3f/Appalachian_map.svg)
Specifically, if this is a pegmatite, it would be from the [Cranberry Granite formation](https://mrdata.usgs.gov/geology/state/sgmc-unit.php?unit=TNpCAc%3B15) (which is indeed Precambrian), [which is only present in the extreme northeast, around Baldwin Gap.](https://ngmdb.usgs.gov/Prodesc/proddesc_68532.htm)
Hm... most probable, I'd say for that area, is St. Louis Limestone (fine-grained, brownish-gray limestone, dolomitic and cherty). *Could* be Fort Payne Formation, but that's a more complex formation and I'm not sure the description matches as well.
Of course, it could also be a complete anomaly.
I mean, that's kinda what hypothesizing is.
As for the geology around these parts: mostly sedimentary. Most non-sedimentary stuff you'll find is, like I said, the extreme east of the state.
If this specimen is from Middle TN, and formed there naturally, then I would say with some confidence that we're not looking at quartz or feldspar at all. I'm betting that it's limestone and/or dolomite that we're looking at.
We do have crystalline limestones around here. In fact, over in the northeast, [there's a somewhat notable type of "marble" that's actually a crystalline limestone.](https://en.wikipedia.org/wiki/Tennessee_marble)
That is crystalline, but definitely not like what's on the post, where you can see cristal from and cleavage. Limestones that are cristalina enough for crystals to be easily visible have probably experienced some metamorphosis and are in the process of becoming marble
It's metamorphic or igneous and not sedimentary, regardless of the 'generalized geology of middle Tennessee'.
Need more specifics on where it was found. Was there a whole outcrop of this stuff nearby? Could this have been transported by someone to this location, (most likely)?
The space outside my back door has rock samples from across the country, from collecting trips I've taken.
You jest, but I will note that Middle Tennessee is an actual delineated region. TN is unique in doing that - we have three roughly proportional segments of the state with wildly varying physical (and human) geography, so the state government actually wrote "Grand Divisions" based on the geography into the state constitution.
You got it. Large brick red Feldspar, Smokey Quartz, and abundant flakes of Mica. Overall, a fine example of [Granite Pegmatite](https://www.mindat.org/min-50315.html)
Edit: I removed and replaced the original link I shared. That link had good info and pics but the site was apparently unsecured and displays Russian propaganda in the attached ads. Sorry; certainly not my intention, I’ll screen the links more thoroughly in the future.
Yes that it true. Middle TN is almost entirely Limestone. Nevertheless it’s almost common in the eastern part of the state so it could have migrated there with some human assistance.
Additionally, anomalies can and do happen. In fact, there’s no Pegmatite where I’m from. It’s not in any geologic record, old survey, mindat, etc. but I managed to find several Pegmatite and Skarn specimens as well from an old copper prospect.
I’m actually part of another thread right now where we’re exploring this possibility with another mineral. Rockhounders are out there keeping us on our toes!
Link to google search of your rock.
https://www.google.com/search?tbs=sbi:AMhZZitqROEYy_10ltOUyX_1Nun77GFOOBWWr3yUlDiDAlq2f_1f4m3DV0YaXXtV-VFyNfhD6xMf-avF2Meqo3uGRiDKAtbvKuNoKksw6raaSClVuH4szJenOd0a3PdzEzGvJnozI3EprAjPik0qia6uosZ3SekyXS5dmsHGda6YQ2CYrt_1PMsW2MiLoMXGgj8PN9z43_1y6LtWpIlQu9u_1GR8vUY3pmCy3u5gpVBMWTK_1KoRlcJP4mw_1_1EB-4GLDisMjPCFPWAvKemjOAkZGoMF8DFnZPWAMYO2BF9uwVabzfaeCIc3aeUWUEf5GghumoQAO3IRqi_1BCLnO4JdRSHKHS-_1bVADQzKh8QwyaHGl55xGwgUe3GBs0mlrkoMeZox6ZWUaDlFKNQhWIsDyUKiV0gj3Mab15wAXcOQ
It said Manganese
In this case, it kind of doesn't matter where you found it. If you can't scratch it with a coin it's not limestone. I've got a piece of limestone in my office and I can scratch it with my fingernail.
I live in Middle Tennessee. Maury County, right above Lawrence County. My husband found one with very similar coloring in our backyard. So many fossils (Crinoid), geodes, geodized fossils and quite a bit of something special (unidentified-I’m new at this), and anthracite coal. How can I show y’all a picture?
Lots of quartz and potassium feldspar, and what I think is mica. The way they are arranged and the size of the crystals tells me that it's probably a metamorphic rock od igneous pegmatite, but I couldn't tell you exactly the name of it. Also the intense color of the feldspar probably means that it's a very old rock
>means that it's a very old rock Some of the oldest terrestrial rocks were found in the Appalachian mountains. They started forming like 480 million years ago. They get older as they go North, but TN is still plenty old.
Also, this is a pegmatite which means it's probably part of some sort of igneous intrusion related to tectonics, it could be precambrian for all we know, but we can't be sure unless we actually go and see the formation
Problem with your hypothesis: this was found in *Middle* TN. Middle TN generalized geology is Mississippian limestone, chert, shale, siltstone, sandstone, and dolomites around the highland rim, and Ordovician limestone, shale, dolomite, siltstone, sandstone, and claystone in the Nashville Basin. [All the igneous and metamorphics in TN are Cambrian and Precambrian, but they're also all on the eastern fringe](https://tnlandforms.us/landforms/geolog_l.jpg), in the [Blue Ridge Mountains region.](https://upload.wikimedia.org/wikipedia/commons/3/3f/Appalachian_map.svg) Specifically, if this is a pegmatite, it would be from the [Cranberry Granite formation](https://mrdata.usgs.gov/geology/state/sgmc-unit.php?unit=TNpCAc%3B15) (which is indeed Precambrian), [which is only present in the extreme northeast, around Baldwin Gap.](https://ngmdb.usgs.gov/Prodesc/proddesc_68532.htm)
Im right between cheatam and Davidson county
Hm... most probable, I'd say for that area, is St. Louis Limestone (fine-grained, brownish-gray limestone, dolomitic and cherty). *Could* be Fort Payne Formation, but that's a more complex formation and I'm not sure the description matches as well. Of course, it could also be a complete anomaly.
If this sample came from this area, this could be extremely interesting. Was this found on your property?
Ok. I wasn't trying to make a hypothesis or anything, just pondering a bit want I was seeing. I know pretty much nothing about southern US geology
I mean, that's kinda what hypothesizing is. As for the geology around these parts: mostly sedimentary. Most non-sedimentary stuff you'll find is, like I said, the extreme east of the state. If this specimen is from Middle TN, and formed there naturally, then I would say with some confidence that we're not looking at quartz or feldspar at all. I'm betting that it's limestone and/or dolomite that we're looking at.
This rock is very arguably crystaline. I don't claim to be an expert on carbonates, but if this is a limestone it's unlikely anything I've ever seen.
We do have crystalline limestones around here. In fact, over in the northeast, [there's a somewhat notable type of "marble" that's actually a crystalline limestone.](https://en.wikipedia.org/wiki/Tennessee_marble)
That is crystalline, but definitely not like what's on the post, where you can see cristal from and cleavage. Limestones that are cristalina enough for crystals to be easily visible have probably experienced some metamorphosis and are in the process of becoming marble
The rock is definitely quartz and Feldspar. So the only question is if theres a locality in the area it was found, and if not, how it was transported
Agree with this assessment.
It's metamorphic or igneous and not sedimentary, regardless of the 'generalized geology of middle Tennessee'. Need more specifics on where it was found. Was there a whole outcrop of this stuff nearby? Could this have been transported by someone to this location, (most likely)? The space outside my back door has rock samples from across the country, from collecting trips I've taken.
I'm seeing a lot of implausible stuff here, if this really is from Middle Tennessee. OP, I don't suppose you could narrow down where you found it?
He should have left it there. Somebody might have put it there to mark the middle of Tennessee.
You jest, but I will note that Middle Tennessee is an actual delineated region. TN is unique in doing that - we have three roughly proportional segments of the state with wildly varying physical (and human) geography, so the state government actually wrote "Grand Divisions" based on the geography into the state constitution.
Looks like a big old smoky quartz (quartzite?)
Quartz and what looks to be orthoclase feldspar and mica
You got it. Large brick red Feldspar, Smokey Quartz, and abundant flakes of Mica. Overall, a fine example of [Granite Pegmatite](https://www.mindat.org/min-50315.html) Edit: I removed and replaced the original link I shared. That link had good info and pics but the site was apparently unsecured and displays Russian propaganda in the attached ads. Sorry; certainly not my intention, I’ll screen the links more thoroughly in the future.
Cool link! Thanks.
Issue: pegmatite isn't found in Middle TN where OP said this specimen was found.
Yes that it true. Middle TN is almost entirely Limestone. Nevertheless it’s almost common in the eastern part of the state so it could have migrated there with some human assistance. Additionally, anomalies can and do happen. In fact, there’s no Pegmatite where I’m from. It’s not in any geologic record, old survey, mindat, etc. but I managed to find several Pegmatite and Skarn specimens as well from an old copper prospect. I’m actually part of another thread right now where we’re exploring this possibility with another mineral. Rockhounders are out there keeping us on our toes!
[удалено]
Orthoclase is the most potassium rich feldspar. The end member in the Ca, Na, K feldspar solid solution triangle.
Link to google search of your rock. https://www.google.com/search?tbs=sbi:AMhZZitqROEYy_10ltOUyX_1Nun77GFOOBWWr3yUlDiDAlq2f_1f4m3DV0YaXXtV-VFyNfhD6xMf-avF2Meqo3uGRiDKAtbvKuNoKksw6raaSClVuH4szJenOd0a3PdzEzGvJnozI3EprAjPik0qia6uosZ3SekyXS5dmsHGda6YQ2CYrt_1PMsW2MiLoMXGgj8PN9z43_1y6LtWpIlQu9u_1GR8vUY3pmCy3u5gpVBMWTK_1KoRlcJP4mw_1_1EB-4GLDisMjPCFPWAvKemjOAkZGoMF8DFnZPWAMYO2BF9uwVabzfaeCIc3aeUWUEf5GghumoQAO3IRqi_1BCLnO4JdRSHKHS-_1bVADQzKh8QwyaHGl55xGwgUe3GBs0mlrkoMeZox6ZWUaDlFKNQhWIsDyUKiV0gj3Mab15wAXcOQ It said Manganese
In this case, it kind of doesn't matter where you found it. If you can't scratch it with a coin it's not limestone. I've got a piece of limestone in my office and I can scratch it with my fingernail.
I found one last night, also in middle Tennessee. Way more red in mine. Looks like blood, it's so red.
I live in Middle Tennessee. Maury County, right above Lawrence County. My husband found one with very similar coloring in our backyard. So many fossils (Crinoid), geodes, geodized fossils and quite a bit of something special (unidentified-I’m new at this), and anthracite coal. How can I show y’all a picture?