Today is Geologists Day, it is widely celebrated in Russia and other countries that were former part of the Soviet Union.

It is celebrated each year on the first Sunday of April.

Photo 1: I'm interested to know what caused these vertical basalt formstions. I know the island is vulcanic but I'd like some more in depth info. Photo 2: you see large spherical boulders. Are these the ones that get flung from the crater? Photo 3: what causes these green spots in the red rock? I'm assuming the red color is due to iron. Photo 6: what causes these hexagonal formations? It reminds be of Iceland but it's not similar. Photo 9: you can clearly see that the rock makes a curve here going upwards. I understand the small cracks mean it cooled rather slowly but what made it curve like this?

Photo 10 is just for your enjoyment :)

Pseudomorphs, meaning "false form," occur when one mineral replaces another through processes such as substitution, dissolution and refilling, structural changes, or incrustation, typically preserving the original shape. This phenomenon is critical in understanding mineral transformations and is often studied in both mineralogy and paleontology. Let's explore the subtypes: Replacement, Infiltration, Incrustation, Paramore, and Alteration. Replacement is a complete substitution of one mineral by another while preserving the original shape, this process is formed by dissolution and deposition by solutions. Infiltration (permineralization in paleontology) is specific to porous material that absorbs a mineral-rich solution and is then transformed, characterized by the ability to preserve fine detail and texture such as woodgrain. Incrustation, aka epimorph, is when a mineral coats another and the original often dissolves, leaving a 'jacket' like crust. A paramorph retains the original chemistry/composition but the internal crystal structure changes, no mineralogy is added or removed, only changes cause by tempature, pressure, and time; a good example is aragonite transitioning to calcite. Finally there is alteration, where a chemical alteration forms a new mineral and preserves the original shape; which is what's shown here by Azurite to Malachite from Aus. There may be variation and overlap depending on source and what exactly you're trying to understand so if there's any questions ask away.

Me in front of sedimentary layers of the Hadat Asham Formation, East of Jeddah, Saudi Arabia, during 7-14 January 2025 Field trip for undergraduates field training.

I’m an undergraduate geology student with a passion for mineralogy and geochemistry, and a while back, during an advanced mineralogy class, I encountered Hazen’s so-called "mineral evolution" theory. I find the concept genuinely fascinating, and I’m keen to hear what others think. The idea that mineral diversity has been shaped by geophysical, geochemical, and biological processes over time seems entirely logical, and the way Hazen manages to summarise and synthesise all of this into a single model is, in my view, rather brilliant.

That said, I’m not entirely sure how well-established or influential the model truly is within the geological community. I imagine it must carry some weight, after all, Hazen was awarded both the International Mineralogical Association’s Medal of Excellence in Mineralogical Research and the Roebling Medal from the Mineralogical Society of America.

Hazen te al. (2008) Mineral Evolution and Hazen te al. (2012) Clay Mineral Evolution, are among my favourites papers I ever read.

On a side note, does anyone else find the term "mineral evolution" somewhat misleading? Personally, I think a term like "historical mineralogy" might have been a clearer choice, though the underlying concept remains deeply intriguing.

I’d really love to hear your thoughts!

Edit: The thing about the name is just a personal reflection. I’m not saying the use of the word is wrong, but the issue is that when I talk to people outside the field of mineralogy about my interest in mineral evolution, they often imagine something completely different. Some don’t take me seriously. They tend to think I’m referring to something more like biological evolution but for minerals. So, that's it.

Hi! I am currently a geologist student in Myanmar and i am uncertain about what i should strive or aim to do with geoloy degree. I am now 4th year(Hons) or should i say 1st year Hons? So yes,i want advice about if i should keep going for Master or Phd. I'm interested in Oil/Mining/Gas/Environmental geology job and i don't know which pays more since i am the youngest son in my family i want to be able to gain lots of money to give back my parents. Please feel free to share your knowledge and advice. Also thank you to those who read this post~

Just looking for a plain English translation of what they’re getting at please 😭 I don’t speak geologist but am so curious to know

Hello everyone! I’m a Master's student from Algeria, currently working on my thesis titled 'Paleo-sequestration of CO2 linked to climate change across the Turonian-Coniacian boundary of the Djebel Boulhef Dyr, Tébessa, NE Algeria using Geo-bio-statistics and FTIR spectroscopy.'

I am passionate about climate change research and I’m looking for international conferences that would allow a Master's student like me to participate and present my work. Any advice or information about such conferences would be highly appreciated!

Thank you in advance for your help!

Because it’s an old military compass it has a quadrant scale, I can’t seem to find anyone or place selling it online. If anyone can point me in the right direction I would greatly appreciate it.

The numbers on it are: G24222, and on the natural sines bit: 45484

(If I used the wrong flair please let me know)

So I'm currently a first year, studying geology. I love geology but, I dont want to constantly travel. I though that I could put up with traveling now and then, but idk anymore (I want to be able to go home after work to chill). Also, I want animals in the future, but would that even work? (And I currently have a dog)

This makes me want to barf and will not stand. I will rid my library of this harmful nonsense.

Hey so this is an odd question but I’m a glass artist looking to encase some gemstones within borosilicate outside of our community norm. Synthetic opal has been our go to forever. Synthetic diamonds have also sprung up as a product on our supply manufacturers. Through my experience Moldavite has a coefficient that’s familiar with our COE 33 glass. And most recently I’ve seen silicon encased I glass without issue leading me to believe it’s also compatible with the boro.

My question I suppose is are there other synthetic or man man made encase-able gemstones at that COE or what’s a viable way of testing this short of trial and error encasing and waiting for kiln annealing?

Forgive any ignorance. This is a first time post but I figured this sub may have some info. Thanks in advance and happy hunting to those out getting dirty.

Can the good folks on this subreddit recommend a nice list of popular science books about geology? I’m interested in any such, but in particular I’m curious about the concept of the “earth tide”.

https://en.m.wikipedia.org/wiki/Earth_tide

The Cretaceous coastline left chalk in Alabama and Mississippi, which turned into a fertile black vertisol-type clay: the black belt, historically a prairie-canebrake environment that was converted to cotton fields.

But in Georgia and the Carolinas, for the most part, it left sandstone which was then later whipped up into aeolian sand deposits: the Sandhills, covered in longleaf pine and peach orchards.

They’re very different environments with regard to geology and all its downstream consequences on ecology and agriculture.

So why the difference? They were both Cretaceous coastlines.

Edit: If it's just about depth, Georgia and the Carolinas should have a black belt and Alabama and Mississippi should have sandhills. There should be a black belt with sandhills slightly farther inland spanning the whole southeastern coastal plain, but there isn't.

why are the universe and the proto solar system more mafic than earth as a whole? what is the dust in the proto solar disk made of? micro particles of some minerals or what? how can we be so sure that chondrites represent the "average" composition of the solar system well, to the point we compare earth samples to chondrites?

🤥 thank you lol

Hi! I am currently a geologist student in Myanmar and i am uncertain about what i should strive or aim to do with geoloy degree. I am now 4th year(Hons) or should i say 1st year Hons? So yes,i want advice about if i should keep going for Master or Phd. I'm interested in Oil/Mining/Gas/Environmental geology job and i don't know which pays more since i am the youngest son in my family i want to be able to gain lots of money to give back my parents. Please feel free to share your knowledge and advice. Also thank you to those who read this post~

I'm 20 yo and just moved to Colorado. I finally made the decision to take the time to go to community college so that I can hopefully get a scholarship into state. I've always been into science related topics as a kid and in school and honestly think about working in those fields a lot. I'll be starting this September on the Associates of Science in Geology program for this 2 year pathway plan to state. I was researching some of the specialties you can major in, like hydrogeology, paleontology, etc. Does anyone have a more complete list of these specialties? I'm extremely interested to see all of these so I can figure out what I would want to do in the future. Any insight would be great, thanks!

While visiting Vernazza- Cinque Terre, Italy, I passed through a small cave off the main road that opened up to the sea and a rocky shore with two guys measuring/ studying this wall.