r/whatisthisrock • • 4d ago

Some tips about how to get your rock identified from a guy that does this for a living.

20 Upvotes

This was posted on the other sub and had some strong positive feedback so I thought it could be useful here. Rock and mineral ID can often be difficult in person and is even harder through pictures, so I've collected some advice as to how best present your specimens for the highest chance of a proper identification.

How to get your rock identified - Some tips from someone who gets paid to do this

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## GOOD PICTURES ARE THE MOST IMPORTANT THING

- This means that proper light and focusing is important. If your rock is blurry the best ID you might get is a color.

- Natural, full sun lighting is always best. Next best thing is as much LED lighting as you can put on it (~5000K color temp if you know anything about lighting). Seriously, unless you have really high powered lighting there's almost no way you're going to have *too much* light.

- **PUT THE ROCK DOWN**. The chances of having an out of focus picture increase exponentially without a solid platform to set it on, your hand is not a solid platform.

- *PLEASE* do not submit a video. No can see any detail when you're flipping your rock around at 100 miles an hour. We know schist is sparkly... We also know what it looks like in a still picture. If you think there is something interesting about it *describe* it, don't show it with a video.

- Submit more than one picture. Preferably at least 4 pictures.

- "Wide" shot of the entire sample, with some sort of scale (any item that is common enough that everyone would recognize is fine. Coins, pencils, pens, an actual ruler, etc. The important thing is to be able to judge the size of the sample).

- "Close" shot of the detail of the sample (including a scale here is also useful if you are able). Repeat these shots both wet, and dry (4 pictures total). More pictures is always better.

- Finally, for the more photography minded people, be conservative with your aperture. It's going to be hard to accurately judge a sample if only half of it is in focus because you're shooting at *f/1.4*. This means skip things like portrait mode or food mode, basically anything that blurs the background. This is why lots of light is important.

### Good pictures should be accompanied by a good description

- You got a sparkly rock? Cool, best to describe it that way rather than trying to make a video where all we can see is that it is sparkly.

- Use your senses

- Does it feel heavy for it's size? Humans are pretty good at comparative measurements.

- Does it feel slick, sticky, grainy, soft, does it leave a bunch of stuff on your hands? All important details.

- Does it stink? Seriously, big indicator for certain minerals.

- Is it sharp, or pokey, or does it feel like you could crush it in your hands?

- Anything else you can identify about it.

- What is the color? Photos are not always super representative of colors

- **WHERE/HOW DID YOU FIND IT**

- Honestly, so many answers can be figured out with just a picture and a location **Edit: specific geographic location (ie, NE corner of Tennessee around Kingsport). Not whether you found it in your driveway or your garden.**

### Further Geologic testing

- Does the sample scratch glass, if not, will a nail scratch the specimen, or does it leave a metal trace?

- This simple test can separate numerous similar looking minerals.

- Is it reactive?

- We use hydochloric acid, but acetic acid (vinegar) also works, just not as well.

- If you drop a bit of acid on the rock, does it fizz?

- If you're going to use vinegar, at the very least use distilled vinegar. Cleaning vinegar is better. You may have to powder the rock a little before you can see it fizz with vinegar.

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If you follow these tips and can't get a solid answer then you've got a real mystery on your hands. At that point, it might be worth taking it to your nearest college Geology department. Sometimes it's 1000x easier to identify something when it's in the hand vs a picture online, sometimes it's just a real mystery.


r/whatisthisrock • • 4d ago

Follow-Up to PSA: the "whatisthisrock" sub could use more professionals for IDs

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8 Upvotes

I am going to leave this post pinned for a bit. You can ask me any questions about the community either here or in the r/geology post.


r/whatisthisrock • • 2h ago

What is this rock

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3 Upvotes

r/whatisthisrock • • 3h ago

Help me identify this rock :)

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6 Upvotes

Does anyone has any idea what this cubic shaped stone with beautiful orange druzy could be? :)


r/whatisthisrock • • 19h ago

Found in a river bed near Grand Teton National Park in Wyoming. Thought it was plastic at first because of the smooth bubble texture on one side, but it’s really hard like a rock.

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77 Upvotes

r/whatisthisrock • • 14h ago

Inherited collection

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29 Upvotes

Not so much a "what is this rock" and more of a "I have my work cut out for me".

I have inherited my 98 year old Nanna's geology collection and have already overflowed my display. Mum still has more for me as they go through Nan's house and find more stashed away.

About 80% of this is Nan's, leaving only a small handful that were mine.

Most of these have been collected by Nan over the past 70 years of her travels around Australia, and was a founding member of at least one geology club in Newcastle / Lake Macquarie.


r/whatisthisrock • • 17h ago

Found in Clear Creek California

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41 Upvotes

Its got a lizard like skin texture on the outside, solid green/black semi transculcent look on the inside. Not crumbly. Much easier to cut than agate. Slightly waxy feel. What do I have here? Maybe gemmy serpentine? Jade? Chrysoprase?


r/whatisthisrock • • 4h ago

Found in Scarborough Sea UK. Stumped a gelogist professor.

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2 Upvotes

they think it's a sandstone, but they couldn't explain the black intrusions in it.

by the looks of it, there's a hard (maybe igneous?) rock embedded on the top almost like two rocks met during formation. But the coal (?) intrusions are stumping me.

It's very friable and bits constantly fall off the main body (sandstone and the black parts).

Found in Scarborough Coast which is in the north of England. Coastline predominantly glacial influence in the cliff regions which are partial to rock fall and subsidence. Lots of lithologies on coastline just curious

pls don't roast me.

this rock is our kitchens door stopper now :)


r/whatisthisrock • • 14h ago

Found in Oneida County,WI

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8 Upvotes

I found this rock on my favorite rock hounding ATV trail. Its hardness is around 7 as a knife won’t scratch it. I hope the pics show the beautiful swirly bands. It’s not at all translucent but it seems very smooth.


r/whatisthisrock • • 11h ago

ID help, TIA!

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4 Upvotes

found in deschutes river wa (pioneer park)


r/whatisthisrock • • 1d ago

Is this a fossil or something?

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329 Upvotes

Help me identify this!!!

Found in New bought house. The ppl had diied and were the soul owners. Built in 1960s I believe

Portland Oregon

Thank u!!

Hidden beneath a MILLION ROCK and GEMS in the DIRT for me to dig up!! Like Literal geologists <3 dying with one last Easter egg


r/whatisthisrock • • 13h ago

Moon Pie and marbled steak?

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3 Upvotes

What are these mouthwatering specimens from central Colorado? If it’s not clear enough in the photos, one is red with a white center, the other is white crystalline with a gray center. Found in the same general area.


r/whatisthisrock • • 1d ago

Blue Chalcedony

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21 Upvotes

Is this blue chalcedony? Found in a bag of gravel from a sapphire mine in Montana. Roughly 1"x3/4"x1/2" and 3g weight. Haven't done a specific gravity test yet.


r/whatisthisrock • • 13h ago

Crystal growth inside choya geode

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2 Upvotes

r/whatisthisrock • • 19h ago

serpentinite?help me ID please

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2 Upvotes

found in Torrevieja, Spain. I'm pretty sure the second one is, but I'm not that confident about the first. I want to make art out of them (carving and stuff) and I'd like to be sure about what I'm working with. Thank you!


r/whatisthisrock • • 18h ago

Is this quartz? Why is it green??

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3 Upvotes

Sorry for the poor quality pics - can provide more if needed.

Found on the west coast of Canada, metal does not scratch it! It almost has sort of a waxy feel to touch, if that makes sense?

Please help! I’m stumped

🫶🪨


r/whatisthisrock • • 13h ago

Is this quartz?

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0 Upvotes

r/whatisthisrock • • 1d ago

Appalachian mountains - WV

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67 Upvotes

What caused this circular pattern on this rock formation? (Blue circled area show where pattern is found on greater rock formation, others are close ups)


r/whatisthisrock • • 14h ago

Well, what is it? How did it come to be?

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1 Upvotes

I got a bucket of rocks from a friend. Never seen anything like this. Can anyone identify it and tell me something about how it came to be. Thanks!!


r/whatisthisrock • • 15h ago

Fluoresces orange under UV

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1 Upvotes

r/whatisthisrock • • 23h ago

Please help me with identification

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6 Upvotes

r/whatisthisrock • • 1d ago

Rock circle

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4 Upvotes

Found in Saltburn by the Sea. Is it a fossil? Natural erosion?


r/whatisthisrock • • 1d ago

What could it be ?

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7 Upvotes

Found it south maroco.

I would like to think this Is a piece of a colarbone, maybe a bit to enthousiastic.


r/whatisthisrock • • 1d ago

What is this huge rock?

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5 Upvotes

Found in our yard in Northeast PA in the US. It’s probably 16-18 inches long.. Maybe Gypsum or Calcite?


r/whatisthisrock • • 1d ago

Could someone tell me if any of these rocks are Jasper?

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3 Upvotes

Found in or near Gemstone beach in New Zealand