Questions tagged [rocks]

Questions about rock types, formation, chemistry, and physics. If you just want help identifying a rock please use the tag "identification-request".

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1answer
302 views

What is this stone or rock that looks like chocolate chip cookie dough? [closed]

Would anyone be able to tell me what kind of stone this is? It looks to have smoky quartz pieces throughout it but I’m not 100% sure. Has anyone seen something like this before? Thanks in advance!
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1answer
161 views

How can I tell the difference between granite and syenite?

(I'm not a geologist, just helping my kids collect rocks).
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1answer
116 views

What is this green and blue rock found on the beach which turns orange when light is shone through it?

I need help identifying what kind of rock this is?
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3answers
239 views

Is this a meteor? It's very heavy for its size [closed]

Here it is. Hope this helps you best image I could take.
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2answers
1k views

What is the identity of this heavy, smooth, shiny black and red rock? [closed]

. It's very shiny and layered. It has rough texture but spots with smooth red colored pieces.
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1answer
113 views

What is the parent rock in this photo? [closed]

Please help find out what this rock formation is and where it is found in the world?
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1answer
71 views

Help me identify this rock [closed]

Please help me identify type, region and name of this rock. Thank you
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1answer
118 views

What rock is this white stone with tendrils like an anemone? [closed]

Could someone please help me identify what this rock is and where it came from? Thank you!
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0answers
4k views

What is this black, shiny, smooth, kind of heavy, metallic rock? [closed]

Its kind of heavy for it size, though not extreme - about two pounds. Looks like a chunk of metal, but not quite sure what it is.
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0answers
104 views

Can someone help me identify this crystal/stone? [closed]

I found this stone whilst on safari in Nairobi. Can anyone help me identify it please?
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1answer
758 views

Is this platinum ore?

Was found in central Mexico. It's very metallic, shiny, showing some streaks of gold and quartz.
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2answers
544 views

What is this white rock with black speckles throughout?

I was wondering if you have any ideas on what kind of rock this might be? I know that it doesn't effervesce with HCl (no reaction with hydrochloric acid at all) and the size and shape of each grain is ...
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1answer
528 views

What kind of rock is this gray and brown weathered cylinder-shaped rock I found near a New York lake?

I found this rock on the beach of a freshwater lake in the Finger Lakes region of New York state and am interested in knowing more about it. It is about 2" tall and 2" wide at widest point. Weighs 14....
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1answer
168 views

Is this a rock or something else?

I found this on the bank of the Fraser River in BC, and at first I thought it was a piece of wood. But when I picked it up, I realized it wasn’t. Does anyone know what formed the rings? Is it even a ...
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0answers
74 views

What is this 6in Nor Cal beach boulder with waxy veins?

Nor Cal beach @ low tide. 6in, photographed wet, post acid wash. Veins look waxy.
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1answer
1k views

How can I distinguish real from fake? (Jade Stone)

How can I be certain this is jade. I bought this rock from a thrift store for 40 bucks. I thought it was a bit pricey for what it is..does anybody have any solid tips on how to clean up the ...
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1answer
241 views

Can someone identify this rock for me? [closed]

Need help identifying this rock I found in river in DR
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0answers
289 views

Puzzle using relative dating principles

This isn't directly looking at a real life ecological example kind of thing, but it requires knowledge of relative dating, so I thought I would come here. Here is what was told: -"Worms" (curved ...
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1answer
367 views

Inorganic Limestone and Inorganic Gypsum

I read that limestone is made from the compaction of marine animals' bones. But, I am unable to find out why limestone could not have been produced from calcium occurring naturally (5th most abundant ...
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1answer
608 views

What kind of rock is this?

We found this today in Acton CA USA. Would like to know what it is.
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1answer
125 views

Can anyone identify this gem or stone please? [closed]

Looking to identify, not sure if it’s precious, semi-precious, or just beautiful… Any answers will be helpful.
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2answers
377 views

What is this complex reddish-brown stone with lighter spots found at a NZ beach?

I found this small stone on a beach on the east cost of the North Island in New Zealand. It's red/brown and has almost gray spots, but also has lots of white crystals coming out of it. It has a dull ...
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1answer
341 views

Help me identify these New Zealand rocks

I found these 2 at the beach on the east coast of the North Island in New Zealand. The white one is beautiful, it sparkles and glimmers and even the brown/pink veins through it sparkle, but it's ...
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1answer
126 views

Is this a meteorite?

Is this a possible meteorite? It's very heavy, magnetic, and the the shiny part shows where I sanded it with a file. Seems to be all metal on the inside.
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1answer
241 views

I found this rock in my back yard. What is it? [closed]

I found this rock in my back yard. I suppose it has been there for ages. It weighs about 10 kg and when I tried to cut it with machinery, I couldn't. Some facts about the rock: I live in Cyprus. It ...
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2answers
584 views

How do quartz veins form?

Is there an association with thrust fault or dormant volcanos and quartz veins? Where are quartz veins likely to occur in nature and how are the formed? Is it possible to identify these veins from ...
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1answer
368 views

Oldest to Newest Bedrock in the USA “road trip”

I am supposed to design a road trip (using major highways) across North America. I have to design a route that starts with the oldest rock of Archean age and finishes with the youngest rock of ...
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2answers
962 views

Radon is a naturally occurring radioactive gas. How does this work?

Radioactive rocks can release a gas called radon when they decay, which can build up in the basements of buildings with serious effects on people's health. Does anybody have information on how radon ...
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1answer
258 views

What is the global distribution of oil filled geodes?

In a general 40 mile radius of Keokuk, Iowa many sedimentary geodes can be found. They are abundant in the Warsaw Formation with the type section at Geode Glenn in Warsaw, Illinois. In one specific ...
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1answer
556 views

Central Texas ore/rock identification

Many of these specimens were found in San Antonio, TX, and the Texas Hillcountry (Kerrville and Bulverde). They seem to have iron content due to rust/oxidized color. Some, but not all, specimens have ...
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1answer
85 views

What is this rock I found being sold in a store?

I was recently on vacation in Hawaii and while there, entered a rock and mineral type store where I saw the rock below. I forgot to ask what it was while I was there and I am unable to go back and do ...
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0answers
74 views

I was wondering if anyone could help me identify this rock

I found this rock along with a few other very similar ones. I found it on an island in Croatia.I was wondering if anyone could tell me the name of the rock.
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3answers
353 views

What is this lavender stone?

Can anyone identify this stone?
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1answer
61 views

What is this rock found close to active volcano

Scratches glass Not affected by sandpaper on the bottom Depending on lighting, intense light, triangles everywhere Violet/light purple fluorescence
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4answers
513 views

What is this Lake Michigan rock?

Rock found along northern Lake Michigan, (Charlevoix, MI). Made up of very thin crystalline layers. There are small, round bubble like bumps that protrude from the surface. Doesn't show well in the ...
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5answers
721 views

Where are the oldest igneous rocks found?

I'm trying to catch up on my homework for earth science, but I'm having a difficult time searching for an answer to my question.
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1answer
43 views

What is the definition of “ground-up shell”?

The archeologists use the term "ground-up shell" to designate a type of temper used for pottery. What is this material? Earth containing fossilized mollusk shells? I noticed the term is also used in ...
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1answer
6k views

How are giant sinkholes filled up?

There are a few impressive photographs of giant sinkholes that appeared in cities, such as this one: However, followup information (e.g. Guatemalan sinkhole) or photographs on how these kind of ...
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2answers
212 views

Identification of dark red mineral

Found in a wooded area after being dug up by my dog. Could not find anything similar online so I thought it best to ask those with far more experience. I'm guessing that it could be petrified wood? I ...
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2answers
261 views

A few questions about glass

A glass, as I understand it, is a material whose solid phase is amorphous and which undergoes a glass transition when heated. My train of thought - and therefore my questions - began with obsidian. ...
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1answer
87 views

ID request; Is this potassium feldspar?

I have a piece of rock that I believe to be potassium feldspar but I'm not certain. The rock leaves a white streak, can scratch glass and be scratched by a penknife and has a pearly luster on ...
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1answer
262 views

Can anyone identify this stone? It was a gift and I can't remember what it is! [closed]

Brown tri color stone Smooth, oblong Please help identify it if if you can!
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2answers
67 views

Phase relation for mantle?

I have information about temperature, pressure, normal and shear stresses, viscosity, conductivity, density, heat capacity and adiabatic heating for a particular area of mantle in the form of 2D ...
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3answers
810 views

Rock ID: silver crystalline rock found in Nevada? [closed]

Found this in a vacant lot...the silver clusters attracted me...then I think there are crystals also...found in Nevada.[
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2answers
1k views

Geology - Rock Identification help please. Melted metal looking rocks in the middle of nowhere

I know nothing about rocks. But I found this and a bunch more that are similar hiking up a river in the jungle of Laos, in SE Asia. If anyone could help me ID it hat would be awesome because we are ...
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2answers
1k views

Rock ID: round, black, heavy, non-magnetic rock from UK [closed]

What is this rock? UK origin, non metallic, heavy
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2answers
96 views

I don't know what this rock is

I got this rock a year ago at a mineral and fossil event, and there was a stand where they where selling 'mystery packages', boxes full of different fossils and minerals. I bought one, and figured out ...
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1answer
63 views

What is this? Found near a lake in Texas. Broken open it's smooth and shiny [closed]

Looks like stacked checkers with ridges.
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2answers
106 views

Odd Inuksuk-like objects

I found some huge objects that are way too big to be inuksuks, in my opinion. The object on the right is very odd because the arms are not straight like they are in most images of inuksuks. and ...
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1answer
98 views

There are cloud identification guides, are there also (guided) rock identification websites?

Seeing all these rock identification questions, got me wondering, is there no straightforward guided rock identification website? In Intro to Geology lab, I remember going through a bit of a process ...