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Rock Identification (imgs.xkcd.com)

'Is it worth anything?' 'I dunno, is the answer to that question worth another $5?'

https://xkcd.com/3068/

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[-] kata1yst@sh.itjust.works 144 points 3 days ago

Better method:

Walk up to geologist, hand them a rock

"Look at this cool agate I found!"

Where "agate" is substituted for any obviously incorrect identification.

[-] pinball_wizard@lemmy.zip 9 points 2 days ago

This approach does save $5.

[-] Geodad@lemm.ee 34 points 3 days ago

Here in Kentucky, it's likely either agate or coal. There isn't much else.

[-] Swedneck@discuss.tchncs.de 12 points 3 days ago

this is why kentuckees have such great teeth, lots of coalgate

[-] ZeffSyde@lemmy.world 6 points 3 days ago

: Makes angry eye contact and points to door:

[-] Angry_Autist@lemmy.world 3 points 3 days ago

You have some ancient opal but very few people find it

[-] Droechai@lemm.ee 26 points 3 days ago

I usually go with meteoric iron, that's specific enough that they want to take a closer look

[-] LovableSidekick@lemmy.world 57 points 3 days ago* (last edited 3 days ago)

At the small college I attended, Geology 101 was known as "Rocks for Jocks" because it was the class jocks took to satisfy their science requirement. In one hallway was a big display board with a bunch of labeled rock samples on it. If you memorized all of them well enough to identify them on the final, you were almost guaranteed to pass. So there were always football jocks standing there studying that board.

[-] Shou@lemmy.world 6 points 3 days ago

Yeah! Science!

[-] usualsuspect191@lemmy.ca 48 points 3 days ago

I usually just say something like "look over there!" and sneakily replace the rock they were tasting to the one I want identified

[-] Viking_Hippie@lemmy.dbzer0.com 24 points 3 days ago
[-] AlpacaChariot@lemmy.world 3 points 2 days ago

Believe it or not, this is a legit thing. I haven't done anything much with rocks*, but here's a good example for soil. If it's fine grained (smaller than sand) and you can't see the particles by eye, you can rub some on your teeth:

Buttery texture --> clay Gritty on the teeth --> silt

Not approved for use on contaminated ground!

  • I'm a structural engineer, but I work closely with geotechnical engineers and do my best to understand it as well
[-] Swedneck@discuss.tchncs.de 7 points 3 days ago* (last edited 3 days ago)

h-hey you're a geologist right? can you uh, identify this c- i mean.. rock? for me?

[-] Xavienth@lemmygrad.ml 9 points 3 days ago

Rocks have distinct textures on the tongue that helps differentiate them. It's not really tasting

[-] negativenull@lemmy.world 11 points 3 days ago

I bet you warn about Land Wars in Asia, don't you?

[-] LovableSidekick@lemmy.world 5 points 3 days ago* (last edited 3 days ago)

I've spent the last two years building up an immunity to garnets in a mica schist.

[-] pseudo@jlai.lu 26 points 3 days ago

They did not lick it. I don't trust that expertise

[-] recklessengagement@lemmy.world 9 points 2 days ago

I wish I had some geologist friends.

[-] aeronmelon@lemmy.world 41 points 3 days ago

Scientists are people, too. Give them the McDonald’s money and they’ll do all sorts of cool things for you.

[-] LostXOR@fedia.io 28 points 3 days ago

Slips a biologist $50 hey could you, like, get ahold of some multi drug resistant m. tuberculosis samples for me? thanks

Small price to pay for being like Arthur Morgan

[-] Geodad@lemm.ee 14 points 3 days ago

Can confirm that the method on the right yeilds better results for anyone who asks me.

[-] LovableSidekick@lemmy.world 7 points 3 days ago

Speaking of this, my wife has a dark gray rock about the size of a silver dollar she found many years ago in our front yard, within a mile of the shore of Puget Sound. It's broken, with a reflective crystalline-looking structure inside, and a magnet attracts it. Anybody know how likely it is to be meteoric iron?

[-] emeralddawn45@discuss.tchncs.de 7 points 3 days ago

Sure as soon as the paypal payment goes through I'll let you know.

[-] Droggelbecher@lemmy.world 4 points 3 days ago* (last edited 3 days ago)

Edit: I was wrong, see below! Shouldn't have assumed simulating active galactic nuclei would make me knowledgeable about asteroids.

Astrophysicist, not a geologist here. Maybe if you sent a pic I might recognize it. But it's kind of unlikely, since afaik crystals from under great pressures, which meteorites don't tend to undergo like that.

[-] Angry_Autist@lemmy.world 3 points 3 days ago

Not only under pressure but under very slow cooling as what happens in the centers of asteroids

The rhomboid crystal structure of meteor iron was set long before that particular rock entered our atmosphere and is visible in many, MANY museum pieces.

[-] BierSoggyBeard@feddit.online 9 points 3 days ago

This can work. But: "Look at this hand sample I found at a prospective mineral mining source. What sort of resources might we find here? I have included a hefty research grant."

[-] Kertyna@feddit.nl 7 points 3 days ago

Jesus Christ, Marie. It's a mineral!

[-] saltnotsugar@lemm.ee 6 points 3 days ago

Yo let me get a dime bag of that geology.

[-] Doolbs@lemmy.world 3 points 3 days ago

I worked in the mining industry for awhile, and we'd just ask the geo to lick the rock to identify it.

[-] podperson@lemm.ee 3 points 3 days ago

The book “Assembling California” by McPhee gives a lot of excellent description about context when it comes to geology. Gets a bit academic at times, but interesting background on California’s crazy geology.

this post was submitted on 27 Mar 2025
608 points (99.5% liked)

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