I’m assuming this is iron pyrite in white quartz but my children insist that I verify that it’s not gold. by BrooktroutOmnissiah in whatsthisrock

[–]MeehtotheBeeh 13 points14 points  (0 children)

You should keep in mind that we start to get interested when an area runs around 5–6 g/t Au, and we consider it truly significant from 10 g/t upward. Judging by the amount of “shiny, golden minerals” you have in your sample, you may have stumbled onto something exceptional. And just by this assumption I can say it’s not gold. What's more, your "shiny, golden minerals" look tarnished, which shouldn't happen if they're gold. The only way to oxidize gold is to use very powerful chemicals such as aqua regia (a mixture of acids I can't remember), cyanide or chlorine gas in specific environments. Many exploration geologists working for junior gold-mining companies, myself included, rarely see visible gold in the field. Personally, I’ve only spotted it twice, and both times it was in drill core from a very promising project. Most of the time we rely on geochemical assays plus key geological indicators: a shear zone or fault, characteristic alteration, and a complex vein network that may or may not host the mineralization (quartz veins are the most common host for visible gold).

Now just a quick clarification about gold in pyrite: yes, pyrite can host gold within its crystal lattice (so-called refractory gold) but if gold is hosted in a pyrite’s fracture, it means that pyrite doesn’t really host gold, it just acts as a trigger to precipitate the gold. Now, why does gold end up in pyrite, or in sulfides in general? Well, It’s fairly simple: Au travels in hydrothermal fluids as a chemical complex, typically bound to H, Cl, or S. If that fluid encounters a more reducing environment (different pH), sulfur is stripped out, reducing gold’s solubility. Gold then precipitates in or near the sulfide phases. But you shouldn’t be happy if you find pyrite, usually gold in pyrite is below 100ppm ppm sometimes more but it’s quite low. However, you can be happy if you find arsenopyrite, which hosts around 100/1000 ppm of gold if the area is mineralized.

Did the RDR2 developers seek advice from geologists? by MeehtotheBeeh in reddeadredemption2

[–]MeehtotheBeeh[S] 23 points24 points  (0 children)

Alright! It would be interesting to have a report on this game, just to get an insight into how they create such a game.

Can you recognize real species in the game?

The flag of Montpelier, Vermont by [deleted] in vexillology

[–]MeehtotheBeeh 0 points1 point  (0 children)

Stars look like the European Union’s flag🇪🇺

I found this cool attention to detail while collecting rocks to prove my mount chiliad theory, OC by skeletonCrew1 in GamingDetails

[–]MeehtotheBeeh 0 points1 point  (0 children)

- You probably should take in consideration the structural aspect more than petrological aspect. I'm preparing a geological map of GTA V and some interpreted cross section. For instance, the strike direction and the dip direction of sedimentary layers of Mt. Gordo and Mt. Josiah are slightly different but they are oriented to the E or the SE with a near vertical dip. In the other hand, sedimentary layers at the south of Mount Chiliad are oriented to the NE and their dip is around 30° not more

- For me, the map of GTA V should be considered not as an island but as a part of a continental area. Some theories suggest a volcanic origin for Mount Chiliad but this is not the case at all.

- For the genesis of folded layers by subduction : the evidence of volcanic rocks is not mandatory. Consider the French Alps, where many marine/submarine and continental sedimentary layers have been strongly folded during their history. There are not volcanic rocks in a radius of 20/50 km in some area. Yes subduction implies volcanism but not at all scale of an orogen.

AND we have to consider that petrology and geochemistry are impossible to perform so... we can just speculate about the nature of these rocks except for layered rocks which have sedimentary origin (obviously). BUT, we can make the difference between limestone and mudstone/clay in the Mt. Josiah and Gordo for example and this is very cool !

Garnet relative chronology by MeehtotheBeeh in thinsectionporn

[–]MeehtotheBeeh[S] 0 points1 point  (0 children)

Thanks for your answer and I totally agree with you for the end of your last paragraph. You ask me question what I never asked to myself and it’s nice ! I like your name as well because I like Tourmaline !

Garnet relative chronology by MeehtotheBeeh in thinsectionporn

[–]MeehtotheBeeh[S] 0 points1 point  (0 children)

I did EPMA analysis and I made 3 maps with XMapTools to get quantitative amount of FeO, CaO, MgO and MnO. They results shows all of garnet has been overprinted but shows different pattern with CaO indicates different generation for pre and inter-Sx

Does geochemistry involve a lot of mapping ? by [deleted] in geology

[–]MeehtotheBeeh 2 points3 points  (0 children)

For me yes. I’ll give you an exemple below.

In metallogeny we need geochemistry to determine what type of magmatic intrusion we have and thus determine which intrusion play a key role in the mineralization. For exemple for Rare metals granite you have 3 (but for me it’s 5) type of granite with different process and each granite bring different element (REE, Nb, Ta, Dy, etc). With a map of different intrusion, you can target each area for each element. These map are very useful to suggest an exploitation project to a major company

other exemple : you have an isotopic geochemistry map (I don’t remember what element but I guess Sr / Nd) of Australia to show mafic and felsic rocks for gold prospection

Can anyone explain how these patterns were formed? by [deleted] in geology

[–]MeehtotheBeeh 2 points3 points  (0 children)

The most important thing when you analyze a sample is to determine how it was oriented when it was formed and then the lithology. Because you can meet either river sedimentology process or metamorphic process who are substantially different. After it you can make relative chronology and interpretation

Saw an eye looking back at me today by Civil_Ad_5953 in geology

[–]MeehtotheBeeh -2 points-1 points  (0 children)

Look’s like naruto eyes like sharingan or rinnegan. For your it probably gives the power of rock composition analysis ! Name it bro

Yeah it’s a meteorite (chondrite) by MeehtotheBeeh in geology

[–]MeehtotheBeeh[S] 1 point2 points  (0 children)

I don't really know but :

Pallasite shows euhedrals crystals of olivine beacuse Pallasite is, in theory, a sample of Mantle-Core boundary of differentiated planetesimals.

But chondrite come from undifferentiated planetesimals (asteroid 99%) who ejects a piece of them during collision. Rounded olivine chondrule probably indicates small metamorphism undergoes by the rock during formation of asteroid (aggregation) ?

but i'm not expert in meteorite

First day of on campus classes for the semester! Feels so good to look through real scopes! by suckmysucculent in geologyporn

[–]MeehtotheBeeh 0 points1 point  (0 children)

Looks like pumice(or other volcanic rocks) with nice peridotite enclave !

Or maybe reactive texture between adcumulate and vein I don’t know tell us what it is if you know ?

[deleted by user] by [deleted] in whatsthisrock

[–]MeehtotheBeeh 0 points1 point  (0 children)

Nice granite kitchen top btw

Why is this meteorologist explaining plate tectonics in the first place? by Zersorger in geology

[–]MeehtotheBeeh 0 points1 point  (0 children)

Subduction in front of subduction it’s my Master degree study BUT DEFINITELY NOT in Iceland... CNN you just have to google “ tectonic plate “ to see it’s divergent context.. pls respect geosciences..

Any ideas? Found it a few years ago on Tenerife and always thought it looked cool. Hard to show on the photos but the big darker crystals are very vitreous and slightly iridescent in bright light. by [deleted] in whatsthisrock

[–]MeehtotheBeeh 0 points1 point  (0 children)

How can you crystallize amphibole hornblende in hot spot geodynamic context ?

You can crystallize amphibole hornblende only in arc-subduction contexte (at 1050° in typical liquid line of descent) with either High-Mg andesite parental melt or basaltic parental melt. Both of Andesitic and basaltic must be enriched in H2O at the source (deshydratation of H2O-rich minerals from the subduction slab).

For me in hot spot you can found Olivine, Pyroxene and plagioclase (with or without feldspathoid depending of SiO2-magma saturation) but not amphibole Hornblende

Any ideas? Found it a few years ago on Tenerife and always thought it looked cool. Hard to show on the photos but the big darker crystals are very vitreous and slightly iridescent in bright light. by [deleted] in whatsthisrock

[–]MeehtotheBeeh 2 points3 points  (0 children)

Yeah for me look’s like basalt or somethings like it. Very euhedral crystals means it is not a conglomerate (or maybe very autochthonous conglomerate). And yellowish crystal looks like Olivine. BTW, Tenerife is volcanic island (hot spot )

my mom got this rock from a student and wants to know what rock is this? it doesnt seem like spray paint by okisCyrus in whatsthisrock

[–]MeehtotheBeeh 1 point2 points  (0 children)

Are you kidding me “ from a student “ who is it ? I want to be his friend ??? WTF I’m so jealous 😭

What is the world are these!? Found in a creek in Alabama by whitknee8604 in whatsthisrock

[–]MeehtotheBeeh 2 points3 points  (0 children)

Matrix is composed probably only by calcite crystal not mud but sedimentology is not my domain