Definitely liked this video! Finally got to see part of your AMAZING collection! So can't wait to see part 2 😁🤘 Very very informative! So cool to watch a video about awesome rocks AND be educated about them. I find it all so very interesting! I like your sorting process. I don't know which was my personal favorite in your collection that you've shown? Too hard to pick. They are all super cool in their own way. I did really like that large black and green one at the end...I believe you said its what bedrock of Arizona looks like. Do you have a favorite type of rock or mineral? Do you tend to like igneous, metamorphic or sedimentary rocks most? Thanks for sharing 😁🤘 Rock on
Thank you, so glad you liked it! I have 4 parts already recorded - did that before I packed all these up to move - but still have some edits. In one of my videos I show my pyrite shelf, I guess that’s one of my favorite minerals. For gemstones I LOVE tourmaline…and garnets…but yeah really hard to pick a favorite! I like the different rock types for different reasons…the emplacement of igneous rocks is the most spectacular to observe, and volcanism is my favorite Earth process to study…metamorphic rocks are so complex and the tectonic history recorded in them is mind-boggling and amazing oh and they have amazing mineral assemblages like garnets, kyanite, corundum, staurolite etc. In school sedimentary rocks and processes were my least favorite, although they do make great land forms…since then I have come to appreciate sedimentary rocks more since they are amazing sources of geologic history and FOSSILS, which I adore! And mineralization in sedimentary rocks can be really interesting, like sandstone uranium ores and the formation of concretions etc. I guess that’s a long way to say I love all rocks, but for different reasons!
@@GeoRockNerd You couldn't of worded that any better. Tourmaline is one of my favorite gems...got plenty of black...no watermelon 😆. I'm looking forward to next 3 in series and seeing the pyrite.
What is retrograde metamorphism? There's so many amazing rocks here. They're all so interesting! Geologically and beautiful to the eye when the beholder appreciates the process, even; f it doesn't appear "pretty" to most, to me, all rocks are beautiful because they survived terrible pressures and perhaps thrown by a volcano, uplifted or rolled to wherever.. so much history in a Rock, LOL Thank You for sharing!!🙋🏻♀️👏😇👍
Prograde metamorphism are the changes made in a rock due to heat/pressure/time during burial of a rock while retrograde metamorphism are the changes seen after prograde metamorphism is complete, when the rock is in the process of being exhumed back to the surface through different tectonic processes.
Hey! Just getting my account here situated a little, hope to get a video going up here soon and join the community! Cool video, its always so interesting to see what others have collected and see that every one is so different! Love it, Subscribed!
@@GeoRockNerd Awesome, thanks! I've got so much to get organized but I wanna get a video out as soon as I can. Trying to still figure out all what's best for filming/editing and all that.
It’s so tough to choose just one! I love them all for different reasons, you know? I have an opal concretion that is pretty high on my list of favorites, and an 11 pound garnet that is way up there on the list! But I also love pyrite in all its forms and tourmaline in all its colors!
@@GeoRockNerd Awesome. I totally understand loving different rocks for different reasons. Like each one has a memory and a story. My favorite so far is a piece of San Juan blue petrified wood that I had polished.
Yeah that’s where a lot of good topaz comes from! The famous topaz in Utah is in tuff. It’s believed that after the tuff is emplaced residual gases start vapor-phase crystallization of various minerals - topaz, garnet, bixbite etc can all grow this way.
I’ve never seen evidence of metamorphism in any of the pegmatites I’ve seen in the field and they are generally thought to be late-stage crystallization of magmatic fluids under supercritical conditions. Not to say a pegmatite can’t be metamorphosed post-formation but they are certainly igneous in nature.
@@GeoRockNerd well I am not sure but always assumed based on the below "While difficult to be certain of derivation of pegmatite in the strictest sense, often pegmatites are referred to as “metamorphic”, “granitic” or “metasomatic”, based on the interpretations of the investigating geologist. Rocks with similar texture to pegmatites are called pegmatitic." Apologies if I am mistaken on that but it gets super muddy from there and with out further reading on the subject I get lost in what appears to be contradictions or different interpretations of this, metamorphic and matasomatic rocks muddy it up pretty well as heat and pressure and fluid change everything
I guess it would depend on what kind of saw you have and what it’s rated to cut, but generally for rock you need diamond blades, or a tile saw. I like blades with a thin kerf so I don’t lose as much material, as compared to tile saw blades which can be quite wide. Good luck!
One of my most ridiculous rockhounding goals is to add a 4th basic category for hydrothermals and evaporates 🤷🏻♂️ Quartz crystal for example they can occur in all types of rocks. The quartz I find is in sedimentary stone but it was created by underlying igneous processes. I certainly don’t think of them the same way I think of limestone with fossils for example. What do you think about this? Am I just nuts?
Quartz veins are hydrothermal generally considered igneous in nature but yes, I have a separate shelf for hydrothermal vein materials. Evaporites are considered sedimentary in nature by most geologists. Fossils are another in-betweener, generally considered sedimentary since they form during diagenesis but also deserving of a category of their own in my opinion. As you can see there can be a lot of overlap between the rock types too - silicification of igneous rocks, metamorphic rocks that retain their original sedimentary features etc.
I have a question for you: Years ago, I found a rock in a thrift shop for like 50 cents, it's some sort of pseudomorph after garnet, sort of a light brown with a very granular texture like sandstone. All I can think of is limonite, but I didn't know it replaced garnet. Any thoughts?
It may just be a weathered almandine garnet. Almandines will literally rust away to dust during the weathering process because they contain a lot of iron. The chemical weathering of garnet is a surface replacement process, sounds like what you may have.
@@GeoRockNerd Thank you. I suppose you could call it ferrous oxide pseudomorph after almandine then if you really stretched the imagination. I totally forgot I had it, found it in a box I hadn't opened in years. It's about golf ball sized, do you think it could have a garnet core, or once it starts is it a through and through type of process?
@@Ken_G. Difficult to say if there would be any garnet left in the middle of it. Is it quite fractured? The more fractures and dissolution it’s undergone the more likely the weathering goes all the way through. But golf ball sized is BIG! Wow!!
I'm sorry, I love the video, but the sulphur in limestone got me, it takes super high heat to calcine limestone and then in the presence of oxygen becomes a calcium oxide which them combines with sulphur dioxide and becomes a calcium sulphate, which is what I think you have there, but it still doesn't explain how it's not geothermic or volcanic, please explain, highschool chemistry and geology can only go so far, please
My understanding is this is biogenetic/epigenetic sulfur from the reduction of gypsum by anaerobic bacteria and/or the oxidation of hydrogen sulfide by groundwater. The limestone is interbedded with gypsum/anhydrite. Hydrogen sulfide is associated with the oil & gas traps in the region which could be a source for the bacteria.
@@GeoRockNerd in Wisconsin at the carne's sinkholes I think they're called running water rehydrating anhydride dissolving its deposits and carrying them away causing sink holes, anhydrite when dissolved creates a calcium sulphide, knowing that and reading your explanation now makes sense, I think, but thank you👍
@@robertbradford3461 It’s very interesting, there’s some papers about the genesis of the sulfur here, definitely look into it if you’re curious for more info!
