Granite. I live in Mount Airy NC the home of the largest open face quarry in the world. I’ve come to gather some samples around town outside the Quarry and I would love if you would check one out.
I live on the Eastern edge of Albuquerque where it butts up against Sandia Crest, 10, 678' of pink granite capped with limestone. The decomposing granite makes a very pleasant crunchy sound under your hiking boot. I've always been fascinated with rocks but don't have the education so I look forward to watching more of your videos to learn what I can.
Very clear and easy to understand. I am trying to teach myself some amateur geology. It helps with my hobby of gold prospecting. Your videos are easy to absorb. 👍👍
Mostly, some argue for other classification systems, but this is the one that most folks use. There are also gradations between the classes as some systems can move from one type to another during formation.
@@geologyjohnson7700 that’s not proof of ether or. Is ther anywhere in the world that has witnessed granite being formed apart from looking at rocks saying that’s how it happened?
@@peterreaney2229 TL;DR; No, we can only look at rocks and experimental evidence. Long version: It's currently near impossible to observe granite forming as it happens many kilometres underground, and at high temperatures and pressures. current models of granite formation are based on observations of the texture, mineralogy, and chemistry of existing granites, combined with lab experiments were synthetic granites are produced. From this combination of observations of natural and synthetic samples, we know that there are only a limited number of ways that rocks with the texture, mineralogy, and chemistry of granites, can form on Earth.
Greetings again from the other side of the Atlantic, in Maryland. You recommended that I check out this granite video because I had posted a granite pegmatite that glows green under UV. Thank you again. By the way, the Shakespeare of German literature, as it were, was Johann W. Goethe. He was an avid amateur geologist. Anyway, he wrote an essay in 1784 called On Granite (Über den Granit). Interesting. He thought it to be the oldest rock and that it must go down to the deepest depths of the earth. He wrote other things about geology, too. Back then it was still possible to learn about everything that was known about geology. He points out that the French and Italian geologists were misidentifing granite. His own definition seems to be still correct, but after seeing your video, I realize now he had no way to distinguish the specific types you outlined. His def, as I recall, was just the three minerals: quartz+feldspar+mica. Which isnt bad for 1784!
Decided to learn a bit about rocks. This was the second video, and 30 seconds in, it was like and subscribe. Nothing is better than get to know stuff through a geologist nerd. You fit the bill, there, and I know you take it as a complement. :D The general information combined with the exposure of your in depth knowledge is making it great to watch. I'd like even more example footage while explaining, in the lines of what you did, just more.
Found you after doing some research. I live in Townsville, Australia. There is a massive pink granite monolith - that I thought was a batholith, but I was wrong - in the middle of the city! It's named Castle Hill. We like it :)
Great Video Thank you , At the time that I am exploring why our ancestors have chosen granite to do rock Art (paintings and rock engravings). I have seen paintings on white Marble as well but granite is the most favorable rocks based on findings and are used as painting attractors Archaeologically. Proposing a joint study !!!!!!!!!!!!!!!!!!
You're welcome. There is also a lot of exciting volcanic rock over in Yellowstone. And there is fascinating geobiology happening in the different hot springs. I've always wanted to visit!
there’s a skyscraper in Houston clad with grey granite blocks from top to bottom. The tallest sky scraper in Houston. Very cool. I like red granite too, from a purely aesthetic perspective. But the grey granite is beautiful too and as a building material seems to be less utilized than your standard classic red granite stuff
That was a really interesting bit of in-depth explanation of what is granite, thanks......but I wish you hadn't stopped when you did. I'm sure you could have told us a lot more. Well I guess I'll just have to subscribe and catch more of what you know about geology.
Are granites formed in plutons? Am trying to understand the current Rocky Mountain landscape, including Pikes Peak. Found your vids only recently; they are wonderful! Thank you!!
Interesting question, that sounds plausible to me. Large crystals require a long slow cooling time. When people do melt experiments, the melt is super cooled quickly for analysis, where as natural melts may take thousands or even millions of years to cool. Usually in melt experiments, a glass is formed as the cooling is so fast. However, I think it might be possible to produce a rhyolite, which is just the fine grained volcanic equivalent of a granite. I will check with my experimental petrology pals and see what they say.
Hi Geology Johnson. Thanks for the video. this was very informative. Do you by any chance have any videos about gases? Is this a part of Geology or does this delve into the realm of maybe meteorology? Just wanted to know more about neon or other elements that make up atmospheres.
I don't have a video about gasses but I can tell you that most of our atmosphere came from volcanic eruptions in the first few million years of the planet forming. Noble gasses like neon are made by radioactive decay of other elements like potassium in minerals in the crust. They escape into the atmosphere through hot springs and volcanic eruptions mostly. Geological gas research is a hot topic as these gasses are used in a lot of our technology.
@@geologyjohnson7700 Ta 🙂 I have 2 lumps of pink granite on my desk but I just picked up a black igneous rock with flat large crystals, not sure what they are yet 🙂
@@geologyjohnson7700 It is 😁 I've put a pic up on my community page and tagged you if you want to have a look, but the tags don't always work on here 🙄🙂🙂
In the expanding (or growing) Earth theory, the granite dome didn't rise up and break through the surface. The whole area domed up, then the dome collapsed. The granite stayed where it was without collapsing.
Definitely check him out he’s a character and really knows his geology I always thought geologists were kinda like boring science teachers but I’ve learned there’s some really interesting geologists and Jeff’s right into it he’s hilarious
Great information I find granite, marble, theirs one area crushed up granite pink in colour started find broken pieces of crystal it has two clevige plans ,cream in colour with green and yellow, white is it feldspar, and white quartzite, orange, pink, theirs a gold coloured as well luv work
When I was driving along i10 (highway located in Arizona, USA) towards Tucson, I stopped at a rest area with weathered granite. It appears that the weathering began with the decomposition of thin inclusions of mica (I'll assume it's akin to biotite), and would form a weathered "opening" for further splitting of the aforementioned granitic bodies. The rest area is near Dragoon Pass.
Sounds cool. That's how I would expect granite to weather in that environment. The dark minerals formed in hot dry oxygen free places so don't like being on the surface.
In New Jersey we have a dwindling amount of “Pompton Pink” A type granite that has pink and green feldspar, quartz and occasionally viens of epidote and something purple. So pretty but not much left.
Do you know why a small lake filled with granite would be a rust color ? I’m very intrigued by this place I have found so many cool rocks there . Great video . Thank you for sharing your knowledge :) 🕊🤍🕊
The dark coloured minerals in the granite contain a lot of iron which gets oxidised causing the rusty colours. What kind of rocks have you found? Sounds cool!
Excellent video, i grabbed my pen and pad. I ve learned in 11:29 video a solid vocabulary and sequence of events that a true geologist would relate, Very well explained and straight to the granite mystery Granite story , that i never knew about. Thanks
Gabbro won't normally have any quartz in it as it crystalises from a magma that has limited amounts of silica, which is what makes quartz. Gabbro will have big milky white square to rectangle plagioclase feldspars, and dark green stubby pyroxenes, and maybe some lighter green olivine too. If you're really lucky, the gabbro will have iridescent labradorite feldspar too. Diorite is chemically halfway between a gabbro (limited silica) and granite (lots of silica), and can look similar to granite. An easy way to check, is to do a rough estimate on how much quartz is there. If the rock looks about 5% quartz it's a diorite. Check out a QAPF diagram to see how much quartz various igneous rocks have and use that as a guide to help you figure them out.
@@LukeyTaylor Yup, just change the silica content and you change the final. It's just like baking cakes, but the cakes are really hot, and not very tasty. ;)
I came here because I was researching why granite represented the way it is in Minecraft I was wondering why it was so pink when I am used to whiter granite And this video was instrumental in helping me, thank you
Wow, realy cool with his metter, what a birth of a man that seems subtle with his metter, that makes people to wonder of his being, a class that mankind registers upon the wider world and get classed for such
I'm from Cornwall. We have granite everywhere. I've found a nice looking lump that has brassy/golden shiny bits in it. I'm trying to work out what it is. Well... I thought it was granite, but who knows?
Hi I found a big piece of pink granite that I was thinking was a pegmatite right up until i watched this video. It's mostly potassium I guess? I was thinking it was manganese feldspar but watching you video totally makes sense. I'm on the west coast british columbia. I found it in a quarry can I leave or photo somewhere or ?
That's definitely somewhere I would expect pink granite. You can leave photos on my facebook or the email in my about section. Make sure there is a scale in the rock photo like a hand or a coin and you give details on where you found it.
Glad you enjoyed the video, granites are neat. Expanding Earth was an interesting idea, but has been abandoned as a model for a while now. It does not explain the observations and data we have now, such as the existence of continents before pangea, the density of the inner Earth, or the motion of the plates etc.
My colleagues create tiny pebbles of granitic material in the lab for study. But these cool so quickly they have no crystals in. The problem is melting that much material which takes a lot of energy, then you have to cool it very slowly - thousands of years or more - to get the nice big crystals. I'm not sure how we could replicate that amount of time and those conditions in the lab...yet.
@@geologyjohnson7700 (yet) now that's intriguing. I wonder sometimes about the rose granites and other granites worked by the ancient Egyptians. They worked with them for hundreds of years so their knowledge of granite must have built up over time. The smooth polishing, the cutting technologies they used, I've read some about geopolymers but not sure how scientific that really is. Fascinating just the same.
I think by combining synthetic obsidian (nitrocellulose + borosilicate, inside a Dyson sphere) with molten calcium (seashells) inside of a Dyson Sphere, maybe with more nitrocellulose in between layers.... You can get different types of Granite...
You would also need a source of additional aluminum, as well potassium. Also, the only Dyson spheres I know about are the science fiction type, is that what you mean?
I've been wondering. If you melt granite, does it make it a new rock? I'm pondering radiometric dating of old rocks. I saw a video where they said that it turned to glass when melted. I'm missing a lot in my mind about how granite and old rocks are formed. And the isotopes. Isotopes give me a thought, just now. How an isotope is created. I kind of understand c14 and other carbon isotopes.
If you melt a granite, you get a "granitic melt" which is the liquid rock. If you allowed it to cool and recrystallise, you get a new rock. Liquid rock turns to glass when it cools down too fast for crystals to form. When we make rocks in the lab, they are always glass because we cool them super quickly. Granites all form from magma by slow cooling and crystallisation deep within the crust which is why they usually have such chunky crystals. Isotopes just occur naturally in the universe as a consequence of the way elements are made in stars.
I just watched a video about granite mountains. I think in Zimbabwe some places have these huge boulder in grey and they'd just be the size of cathedrals right in the middle of nowhere and I think they might have been this granite
Hi, below you mention that Ironstone is a specialty and I thought to ask if the stuff I find in Mount Shasta, (which erupted long ago) could be Ironstone or iron ore? It is a non-porous, solid dark brown color with pockets formed by medium sized bubbles about 1/4 to 1 inch, molten in appearance with some rusty parts and a bit heavier than stone... um, sounds like metal huh? I'll try a magnet on it.
That sounds like volcanic scoria or vesicular lava that has been oxidised. Oxidised volcanic rocks like this are one source of iron ore and would be common around a volcano like Mount Shasta.
This is unlikely as the minerals and textures in granite indicate that it forms from the cooling and crystalisation of liquid rock deep in the earth and at temperatures of over 800 degrees C. Any fossils in the rocks that melt to form the granite magma, or in the rock around intruding granite, are sadly usually destroyed in the process.
The standard explanation for granite formation doesn't match what I observe. Other igneous rocks have a distinct "melted homogeneous" look. Lay out samples of all the minerals it's composed of next to the granite sample and it looks like each of the minerals were broken up and squeezed together without any melting, fracturing or obvious matrix. Same for Gabbro and Diorite. Fractional Crystallization as an explanation is intriguing. I just don't understand how the crystals nor the gaps between crystals of the same type formed when they were part of the same melt. It would seem even very slow cooling would be more likely to result in the formation of something like Rhyolite. Granite is certainly a very special rock.
I think that's why granite was known as "the granite problem" for so long. Fractional crystalisation helps explain I -type granites, S and maybe M-types probably also form from alteration of preexisting material too. It helps me to think of magma as a slush of crystals and liquid churning around as it moves through the crust which helps explain many of the textures I've seen, e.g., the textures you describe, and things I've seen such as flow banding and grain alignment.
Yup, that's fractional crystalisation. It can take places in stages separated by long time periods while the magma migrates through through the crust. Early crystals can get transport damanged, or chemically eroded and smooshed around before the next batch of minerals crystalises
@@jamieingels1190 they both form by crystallisation, just at very different temperatures, so that's not a bad analogy. In geology, cements are pretty common in sedimentary rocks.
Different granites form in different settings, S-types in continental collisions, I-types in island arcs, back arcs, and even rift settings, A-types in thick continental crust...Check out Robin Gills book on igneous rocks and processes.
I've seen some granites that were only 15-20 million years old from the Himalayas. They were just as hard as the older ones because it's the mineral composition that determines the hardness.
Yeah, you can make artificial crystaline rocks by putting powder in a little capsule and then heating it in a special oven. You only get a tiny bit though and the crystals are microscopic. Not much use to look at, but very useful for micro- analysis.
Do you mean resonate from vibrations if you hit it? Or if a wave passes through it from a sound or a quake for e.g? Either way I suspect that it would be different for each sample because granite is an aggregate of different minerals with different crystal structures. The type and proportion of those minerals would determine how well energy is propagated through a particular sample, and then if that sample has any resonant frequencies.
@@geologyjohnson7700 no I mean there are resonance patterns to everything and those symbols look like resonance patterns certain sound vibration and frequency create these patterns now what if those patterns are a key maybe a portal opens maybe its how they sofened the granite maybe they were able to make the huge blocks float like opera singers can shatter a crystal glass by hitting the resonance of that glass with their voice Nikola tesla said sound frequency and vibration everything has one there are experiments on you tube doing this that's why I said they look like resonance patterns
Hi, great video I would really love your help! Blue granite, is it formed near volcanic activity? I'm not a geologist so I'm not sure if I'm saying it correctly lol Why can't have magnetic properties?
Blue granite isn't really granite, it's a common name marketing name for different kinds of blue igneous rocks such as monazite and larvikite. The blue colour comes from minerals like sodalite, and labradorite. These rocks crystalise slowly from magma deep underground like a granite does, but they don't have enough aluminium or silica to be classed as granites. Still very nice to look at though. They are not magnetic because the don't have enough elemental iron or magnetic minerals in them like magnetite. Instead, the iron in these rocks is in the silicate minerals so it's not magnetic.
Depends on the example, but generally it's not very radioactive. The radioactivity is from within microscopic crystals within the granite. The amount of radiation emitted is usually tiny so they are safe to use in buildings or have in your collection.
We have lots of ideas about how granite forms, and a lot of evidence from rocks and experiments to support those ideas. Unfortunately, we can't yet go into magma chambers or the cores of mountains to watch those processes happening in real time :( . That's why I study mud, it's pretty easy to watch it form most of the time. ;)
You are not a dweeb! You are smart! I have a crystal with a heart shaped rock inside! Can I send you pictures of it so you can help me know more about it?
Thanks! It's ok though, I'm being silly. We all like being dweebs with our rocks and hobbies. :) Sounds like a neat rock! You can try sending a picture to my geology johnson facebook page, but that doesnt always work. You could also try making a video and posting it on youtube or tiktok.
Question for you rock guy, Do you think in an envirnmoent where you have all the minerals needed to create rose granite lets say....were in one area like a beach.....but no water.....in powder form. Now what if you added a little bit of sea water into that mix.....could you then form that into a playdough. And if you can make it into a concrete(similar to roman concrete)....is it possible that most of the rose granite taken out of Azwan Quarry was in powder form.....carried up to Cairo? Then formed with huge blocks molds...like bricks.....now i had an theory.....that a clay block that is still maluable could be cut and shaped with copper wire and copper wire tools like scupters use. Just a High dude over here thinking about the mysteries of the world. Haha
You've bascially described about clastic sedimentary rocks are made. Mineral grains from an eroded rock like a granite get cemented together by minerals that grow out of (usually) sea water. The size of the grain determines what the rock is called, e.g. Sand sized grains = sandstone, clay sized grains = mudstone. But the resulting rock is a sedimentary rock, and no longer a granite (or whatever rock was eroded to make the grains). That's why a lot of mudstones and sandstones usually have the same minerals and chemistry as granite. The second thing you describe is basically how clay bricks have been made for thousands of years. But instead of grinding up existing granite, people find deposits of clay that was already eroded from granite. I don't know much about building materials in Cairo tbh, but I know that a lot of the big monuments like the pyramids are made of the local limestone which has lots of fossils in it. Limestone is relatively easy to cut and polish, and you can make cement from it. A stack of limestone blocks will eventually naturally cement together just from the action of rain etc if given long enough.
The creature on the shirt is a microscopic fossil called Tappania plana which lived during the Proterozoic eon. The very nerdy joke is that a theme park based on Proterozoic organisms would mostly be microscopic.
I don't know, for sure, but I don't think so. If a big enough asteroid hit a silica and aluminium rich bedrock, some of the rock would melt for sure. But the resulting melt would probably cool so fast, it would be glass, or too fine grained to be a granite - perhaps you could class it as a rhyolite? I will have a look into it because it's an interesting question!
I don't know anyone researching this aspect, but try searching using google scholar. There will be a lot of results so you can then focus on the things that interest you most.
Great video. Just one thing. I have a little problem with ADHD and I kept getting distracted by the reversed lettering on your chair and your T-shirt. I've grown to love geology, but I hate my wandering eye and mind.
One day I was siting in front my computer and asked this fundamental question. What is granite? And the RU-vid has spoken as always. Sometimes I think that before RU-vid people were 90% dumber and cut off from knowledge. This is the bright side of modern times among all the rest that is not so fortune these days.
Hello Geologist Johnson, I sent you a message...you replied to me ( I hope it was you ) ! You asked me to send videos of 2 fossils I have for you to give me your take on them, but now I can't find the messages ! Are you the person I'm hoping you are ? I would like to send the videos to you. Thank you for your time ! Melanie Browne-Klein
Hi Melanie, I replied to your comment on this video, is that the message you mean? I've just added a contact link on the about page, you can try sending the video through there. :) ru-vid.com/show-UC0PmbdI2FaKqAfugdViw9zQabout
It's only a problem if you don't believe in the bible. someone please explain to me how primordial radionucleides are captured in granite with such an allegedly non-instant cooling and solidifying process.
Primordial radionuclides have half lives of billions of years, granites cool at rates of thousands to millions of years which is *relatively* slow compared to a lava erupting on or near the surface, but *relatively* fast compared to the decay of long lasting radionuclides. This means that the nuclides can be incorporated into the rock as the magma cools and crystalises allowing us to place age constraints on those events. :)
This guy uses terms which are unfamiliar to the average person and he doesn’t explain them. He is basically preaching to a choir of geologists, who already know all of this stuff. So there is little to learn from this video.
I will try and remember to explain technical terms in future. Folks can always leave a comment to ask about stuff I didn't explain, or what terms mean.