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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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Tectonic Plate Movement

I have been unable to find a clear answer to the following basic question. How are continental shelves formed - What type of boundary occurs (convergent, divegent, oceanic to continental, etc) and ...
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Help identifying rock [on hold]

I found this rock near a creek bed on the Cumberland plateau about 30 miles north of chattanooga. There area is coal bearing. It has odd knobs and a cavity that goes through it. Seems moderately ...
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Please help me identify this stone? [on hold]

Please help me identify this stone
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37 views

Please identify this rock

I found this rock along the Illinois river basin in cave junction, oregon. It was laying on the top layer of a massive beach of rock. It's shape is what drew me too it, then after closer inspection ...
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Can anyone tell me the name of this stone? [closed]

Can anyone please tell me what this stone is? Any other information on it would be helpful as well. Thank you!
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What is this rock it is dark dark blue? [closed]

This is really weird tell me what it is.
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0answers
37 views

What is in this rock?

There were many, many examples of this, my photo simply shows a situation where I had even light and time to take a photo without making anyone wait for me. The basic rock is obviously sandstone. ...
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33 views

Identify rock found on beach in Florida [closed]

This rock was found in Florida on the beach on top of the sand. There were no others found. Color of rock is white, the outer rim is clear (see through) the inner layer is solid. The inner layer is ...
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1answer
32 views

Identify rock, found in Florida

Round with crystal looking around it, hard. Seems to have layers in the center. The inside is smooth and the outside layer is textured. The white layers go all the way through the rock. Found on the ...
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1answer
44 views

What kind of rock is this?? White rock [closed]

What kind of rock is this?? Found laying on the surface of gravel.
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1answer
50 views

Help identify my redbrown rock with crystal like formation on the inside

This rock is red/orange/brown in color. It is slightly clear/translucent when held up to light. Will not scratch with a knife. Has a crystal like structure on the inside.
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1answer
38 views

What is the difference between subvolcanic rocks and plutonic rocks?

I'm studying Plutonic (Intrusive) rocks and i really dont understand the difference between PLutonic Rocks that form in Sills and Dikes from the so called subvolcanic rocks, also known as a ...
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1answer
42 views

Mineral/rock identification [closed]

I found this rock in the Himalayan region in India. It was on the roadside of a hill that we were trekking. It has a silver lustre. It has a hardness of 5.5(I can scratch it with a knife blade).it has ...
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1answer
48 views

Please Help Identify My Rock

This rock is smooth, heavy and dark grey/black in color with white blotches which are different in shape and size and are also porous. It scratches by a knife and I found it in with many pails of ...
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Rock ID: black, white and orange, from Malaga, Spain

I picked up some very interesting rocks and pebbles on the beach in Malaga, Spain this summer. They are predominately flat and colored dark grey crisscrossed with stripes of orange and white. The dark ...
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0answers
36 views

What kind of rock/crystals are these? [closed]

I'm trying to figure out what this rock is. I've looked all over for a similar crystal formation and I'm coming up with a conclusion it's a type of geode but can't find any with a lot of cavities ...
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1answer
167 views

What is this yellow stone

I found this yellow stone in a creek.It was easy to break by slamming it against another stone and has evenly spaced crystal clear grains.They are very clear that under the sun I thought that water ...
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0answers
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What is the toughest rock?

I wonder which rock is most resistant to being cracked apart by a hammer, in other words, what is the toughest rock? What rock is most difficult to mine through? Hardness is different than toughness, ...
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1answer
37 views

What is this stone or mineral it's light but strong

The other side is just cyan color I don't know where this stone is from Any help is appreciated
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1answer
47 views

What is this translucent blue-green oblong crystal?

I think it might be aventurine of some sort, but I'm not sure. Hardness: It is harder than a steel nail file. The file leaves a track, but it rubs off, leaving no mark. I scraped it on the bottom ...
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3answers
156 views

Making a local geological field trip an interesting and educational event for children?

I have no expertise in geology or earth science, but I would like to do a "field trip" with my home-schooled young children (under age 10) where I could teach them about geology from a hands-on ...
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1answer
87 views

What type of ore is this?

I have found this metal somewhere in a semi-desert area in Ethiopia. The place has no mountains and has no human contact yet. It is magnetic and has some rust on the top which can be removed using ...
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1answer
64 views

Rock identification: gray with small dark lines/inclusions all over

Gray stones with short small dark shiny lines all over it. Found it on the beaches of Newport Rhode Island.
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1answer
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What is this figurine made of:

Have several of these animal figurines, MADE IN USSR on bottom. Can't figure out what type of rock it is made from. Any ideas?
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2answers
111 views

Could one say that granites are metamorphic rocks, or not at all?

In my old textbooks, granites used to be part of the metamorphic rocks. Is this still true or not ? If not fully true, to which extent ? Could someone point me towards clear examples or definitions ...
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1answer
104 views

Identification: mystery rock with golden features and shimmer

I found this rock in our backyard in Germany. As our garden is filled with bushes it was very oddly placed and I have carried this rock around with me ever since, wondering what sort of rock it might ...
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1answer
184 views

Help Identifying this rock with a rainbow

I found this rock and I want to know what it is. It looks like green-grey and when I put one side of the rock on the sun, it changes its colors on that side. Thanks
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0answers
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What a place that sells rocks is called [closed]

If a nursery sells plants, I'm wondering what a place that sells rocks is called. Something where they offer rocks of various sizes like this: Well, those are all river rocks, but I'm wondering about ...
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1answer
58 views

I need help with these geode like rocks [closed]

I found these rocks in my pasture and was excited because I thought I had found some geodes. The rocks were in a sandy bank and looked like eggs sticking out of the bank. I am located in Ness County ...
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1answer
77 views

Iron like rock in western pa, is this hematite?

Found this years ago when digging a garden here in western pa, finaly decided to figure out what it is. Its dull, but has thousands of very tiny crystaline specs, very ferus, even the “rocky” looking ...
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2answers
69 views

Can someone help me to i identify this rock found in macedonia [closed]

Can someone help me identify this rock? Also, will it react to acid?
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2answers
148 views

I found this strange spherical stone in Gillette Wyoming. I have no idea what it is. Please help.

These are recent pictures of it. It’s heavy, I see small minerals that catch the light in it, very bumpy, spherical, doesn’t seem to be magnetic, I was falling down a deep trench and kicked it up at ...
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1answer
56 views

What kind of purple stone is this?

I found this stone and I do not know what type of stone is this?
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1answer
148 views

heavy, brown, rock with crystals, please help identify

please help identify this rock. it is heavier than most. dark brown color. picture is shown with streak test. found in Philadelphia pa. at home demolition site. crystals seem to be different type and ...
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0answers
69 views

Rock identification - origin unknown

I'm trying to identify this rock. It's fairly fine-grained and has a green tint. It's fairly heavy for its size, I cannot scratch it with a figernail but I can make a scratch with a knife. The rock is ...
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1answer
65 views

What kind of rock or stone is this? Where did it come from?

I found this on the side of the road in Oregon, i think it was left or forgoten about thats why it was left there but it has crystal pockets, multiple colors, some smooth sides, perfect circles and ...
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1answer
68 views

What kind of stone is this? Can I safely test it with acid?

Found in Wisconsin, top appears black to dark blue, slightly translucent at the edges. Is it safe to use acid to test this material?
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1answer
60 views

Please help me ID this rock

Can you help me identify the type of magic egg in this photo?
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2answers
109 views

Can someone help me to identify this rock?

A-density:2.66g/cm3,weight:370g,rock attract the magnet for this rock I do not have the density currently
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1answer
330 views

Help Identify My Rock Please [closed]

My daughter found this rock in a field and I am curious to know what exactly it is...please help!! Its like a white color (almost like concrete) but has specks of shiny blue and clear stones in it ...
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1answer
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Glacial erratic - Granite or Gneiss?

This boulder is a glacial erratic in New Jersey. Can anyone tell if it's granite or gneiss? When you look at from the side, there appears to be foliation... but when you look at from the top or other ...
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3answers
202 views

How is this crumbly crystal-rich rock formed?

I found this crumbly rock embedded in the channel walls of a small creek in Everett, WA, USA. (North Creek that flows through McCollum Park.) If possible, I'd like to know how the rock formed... what ...
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1answer
179 views

What is this red rock with crystal white inside?

I found this rock in the desert. I found similar rocks that are crystal white on the inside, but this one is rough on the outside and all the others are smooth. Plus all the rough rocks doesn’t have a ...
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1answer
70 views

Can anyone help me identify this rock?

This is probably just something really common and boring to most people, but I was intrigued so I thought I might as well ask now I can. When I was in Portugal (I don’t know specifically where we were)...
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3answers
111 views

Can anyone help me identify these rocks please?

I apologize for any errors in my pictures or writing. My first post. [
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64 views

Whats this stone?

Found it couple days ago and it amazes me how smooth the surface is but cant identify it please help me. Found it in north germany near a lake on a trip there.
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1answer
102 views

Need help identifying this rock

I need a little help identifying this rock. It was found somewhere in the Sahara Desert. It is very hard and leaves a beige streak on a steel file (might be the concretized dirt covering it). The ...
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1answer
180 views

Rock/mineral identification - smooth black inside

It’s yellow and grey on the outside but smooth and black on the inside. Very roughly 2.27 g/ml Just curious, it almost like sea glass on the inside but it’s far too dense.
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2answers
128 views

Help me figure out what this purple rock is

I found this in the ground at a job site in blue springs mo . Its purple with darker purple lines through it like growth marks on a tree. It is about the size of a large loaf of bread 7 inches across ...
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1answer
66 views

Could you help me identify these rocks please

Found these whilst walking around Warwickshire please could you help.thanks