You can support my videos by clicking on the "Thanks" button just above (right of Like button) or by going here: www.paypal.com/donate/?hosted_button_id=EWUSLG3GBS5W8 I appreciate your support, comments, and encouragement as we learn together.

Great series! You are doing what KZfaq was made for.

Thanks for these ID videos. They are immensely helpful to amateurs like myself.

Loved this series! This is so much more helpful to me than what I get from written guides, alone. Many thanks!

Another great presentation. Thank you Prof. Willsey!

Thanks for showing this Willsey. One key word to remember with metamorphic rock is compression. These rocks are under the earths surface and layers have crushed them over time and weathered them to change them. An example of metamorphic rock is coal when coal was formed it started out as peat you compress peat you get lignite, you compress lignite you get bituminous, and you compress bituminous you get anthracite. One more step is needed to turn coal into a crystal it needs to be heated close to the melting point but not enough to destroy it because when anthracite is heated and compressed it turns to diamonds and thats how they find them. Same process happens with quartzite crystals before that they were sandstone it all has to do with compression.

I've been following this rock Id series. I found this explanation of metamorphism exceptionally clear and easy to understand. Thankfully I have put the id videos into their own playlist. It has been awhile since I did the first videos. I'm discovering that I need to go back and review them. Old brains I find need more repetition. I'm trying as I watch geology videos to pick out the types of rocks on my own. I'm currently enjoying your Iceland series. Any new videos, such as this one I will watch as soon as I can each day. Thanks.

Thanks! These bite sized lessons are great! Good to see the story behind the rocks out there.

You are just perfect teacher! It is so awesome that I can be your student, although I live on the opposite side of the planer (: My country Estonia has an issue with metheorites - we have lots of impact places. One of them created an island - Osmussaar ( locals called it "grave of Odin"). On the island we have huge pieces of brecha created by the impact, and as a further consiquence - all limestone island is covered with huge and long quarcite "networks" with pyrite and fossils right under your feet.

Yay! Totally awesome. Makes my head spin. 😂 Makes me more a better interpretive guide. Thank you, Shawn.

Thank you for your videos Shawn!! ❤

Yessir - the story is the thing! Thanks!

Ah ha! Low, med, high grade! Important pieces to remember. Hopefully one day I'll pick up a rock and read it. Correctly. You're a great teacher. 👏🏻 Thank you!

THANK YOU VERY CLEAR TEACHING!

Love your knowledge and I’ve learned so much looking forward to going out and identifying earth processes near me. Thanks Shawn

You have a way of explaining these complex processes and making them so understandable. I have interested in the more complex Geological Processes and you have made them so understandable. Now I know why and how North Carolina and Virginia have such beautiful Gneiss. What is also interesting is that most Igneous rocks on the US East Coast have undergone some kind of Metamorphosis.

Very interesting! That was a lot great info, gave me a much better picture of these types of rock!

I'm a subscriber and absolutely love your amazing videos! I love hiking and have visited many national parks, and I have a great need to understand everything about the rock formations, and your videos really help me have better understanding of these formations before and after my trips! So, thank you so much for sharing your passion and knowledge to help us have greater appreciation for the geological wonders of our earth!

Thanks for this series. It's just what I've been looking for to help me understand the rocks that I collect. PS: This is the first time I've heard someone describe a meteor impact as "sexy". That's cute. I find them fascinating too!

Gneiss video. Thanks Shawn.

Good presentation.

This explains so much about the immense variety of rocks out there. Thank you!

AWESOME" Tabletop Breakdown" 10 THUMBZZZUUUPPP!!! from the Clearwater Embayment! jd

This video was exactly what I've been looking for, thank you! I will be checking out the Igneous & sedentary videos too 😁

Thank you so much for these helpful videos Shawn. Hopefully they will help me pass the Rocks and Mineral Quiz!

I hung in there! Thanks Shawn. I've been traveling to NYC lately. The geology of that area is really amazing. There's a lot of gneiss there.

This was so fascinating and informative, thank you.

Awesome video sir. Thank you for sharing.

What a treat ! Thanks for the hard work. I live on top of the Alhambra formation in southern Spain. This video really helps getting to grips with the rock types that you find every day in the walls and river beds.

Thank you so much Shawn for these videos. I've been looking forward to this one because I find metamorphic rocks quite interesting. Now I have a question that I hope you can answer or lead me to a source for further information. Keep in mind, geology is just a hobby and I have no formal science background. I have several samples of foliated gneiss. I understand that the pressure is forcing minerals (especially columnar types) to line-up perpendicular to the stress. What I can't seem to wrap my head around is why the randomly distributed minerals will separate from each other, then recombine with common minerals to form the banding. I have samples where the biotite is almost perfectly uniform, the white plagioclase and quartz seems to be another band and then even a clear band of almost pure pink K-spar. I just don't get it. How is this occurring? I can't understand how the pressure would cause the minerals to literally change location in the rock and group together. Maybe I'm dense (like a metamorphic rock) but I'm lost. Perhaps you can explain this in the next episode. I would welcome any input from other viewers. Again thank you for your hard work.

Very interesting thank you.

I want to see the impact metamorphosis!!! I want all examples… I’m so curious to see what they look like! I’ve seen a couple examples, but I want to see the hand specimen, the thin section, and a cut piece.. I know there’s several types of them.. I’d like to see them all!!! Please??

That was awesome. Thank you.

Thanks!

Been looking forward to this one. I've learned a lot about the different types of rock or Lithic States of mountains and canyons I've seen through your channel Shawn. This was too short Shawn. Hmm, over 18 minutes, I guess it wasn't too short.🤣 I only discovered your channel a few months ago and I think I've seen them all. I was in Iceland last year during the second Fagradsfjall eruption and I felt bad when you said you slept in your car to save hotel costs, which in and around Reykjavik are pretty steep and especially during the eruption they went up. But if you drive an hour or so north of Reykjavik, room rates drop quite a bit the further north you go and if you don't stay on the coast they are less than $100 a night and could include breakfast and sometimes even supper.

Thank you Professor. You are helping me build an understanding of a granite that I have wondered about - Verde Butterfly. I have a beautiful polished slab as a bartop that I have struggled to understand. After learning from you, I speculate it is a high-grade metamorphic rock of folliated feldspar crystals with a random orientation to one another. As minerals have different temperatures where they reduce and are 'liberated' to migrate and accumulate, that explains the abundant garnet crystals in this stone. Because of the high temperatures associated with high-grade metamorphic rocks I guess the white constituent to be quartz. Any further understanding of that stone would be greatly appreciated. I have poured over information available on the net, and learning the fundamental geology of minerals from you has been the most enlightening.

This info may be irrelevant to some, but I think it matters.

If possible, can you please post your videos a little more rapidly, as I have my Science Olympiad Rocks & Minerals competition on Thursday (3/16/23)? I find your videos very helpful! Thanks!

THANK S

👍

Correct me if I'm wrong, but around 14:35, you say that gneiss and slate share the same parent rock. Perhaps they share the same "ancestor" rock, but doesn't shale grade into slate which grades into phyllite which grades into schist which then finally grades into gneiss?

Where are some places to find metamorphic rocks in the West? I’m interested in seeing these for myself.

Phyllite is burial metamorphism?

Thanks! And how do you differentiate mylonite from gneiss? I'm a bit confused about that

i want your autograph.

10:09 So if y’all anglophone professors have to teach the students to spell gneiss with a G, why not go full hog and just pronounce it too, like in the original language it comes from? 🤔😄

Thank you, your video's are great exactly what I was searching for plus there's an abundance of them!

Thanks!

Thanks!

Thanks!

Thanks!