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Questions tagged [minerals]

The tag has no usage guidance.

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How are minerals classified?

What is exactly done to classify minerals in Earth Sciences such as Geology? How can it be known if one mineral is the same of another should they be visually different?
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Please help me identify this stone? [on hold]

Please help me identify this stone
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1answer
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How salty can snow/sleet be?

Can enough salt particulates be in the air to create salty snow or ice that is undrinkable? Will ice form in sub zero temperatures through condensation in salty air?
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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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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
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What is cluster situation with respect to sand mining?

Guideline on handling cluster issues : The original Environmental Impact Assessment ( EIA ) notification does not provide for the procedure to handle cluster situation, which has been proposed in ...
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1answer
43 views

Preservation of clay items

I have a general question which may sound naive: archeologists eg in Ancient Greece take a lot of information from preserved pottery they found. What physical attributes of ceramic items made of clay ...
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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
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Where to start searching to find more radioactive minerals?

I'm pretty new to all this... I've recently purchased a Geiger counter, and am hoping to locate rocks like pitchblende and other radioactive minerals for my collection. I'm based in the North West ...
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1answer
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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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2answers
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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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0answers
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Help Identifying this Mineral? [closed]

I have the following rock/mineral but can't seem to identify. Anybody have an idea what it might be? It's heavy, 3"x3", nonmagnetic (but slightly repels a neodymium magnet), blackish in color with ...
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2answers
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What is this stratefied limestone sphere?

What is this stone from the alps of provence? It's two spheres, one of them is made of at least 25 layers.
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1answer
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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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1answer
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How does palingenetic fusion occur in rock?

As far as charnockites are concerned, granitic charnockites are formed due to palingenetic fusion and metasomatism, while granulitic charnockites are formed due to high grade metamorphism. When I ...
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1answer
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Mineral identification; black & metallic

During a recent trip to the Portuguese island of Madeira, I found a couple of interesting rocks on a beach. Both the rocks pictured in this question contain the same black mineral. I first guessed ...
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2answers
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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
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Unidentified mineral found in France

(I am not a native english speaker, so I'm not really aware of the specific terminology.) A few years back, I found an unidentified rock on a beach in Normandie (France). It looks and feels (texture-...
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1answer
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Identify this transparent brown rock

t The rocks are pretty small they are dark brown and comoleyelybsee through.
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1answer
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Please help me identify this stone (Look like some kind of quartz, but I'm not sure.)

My young sister found this stone on a street and she asked me what type it is. And I really don't know. It was found in Western Ukraine, in North Galicia. But it may be that it was brought here from ...
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0answers
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Identifying rocks, minerals

I am sorry to bother you.. before passing away, my grandfather gave me a special box that contained all types of beautiful, colorful rocks and minerals. I am having a hard time identifying them! Could ...
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Please help me with the identification of this rock

What is it? It has what looks like white glitter its ugly dark brown and some orange heavy..
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1answer
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What is the type of stone/mineral in this necklace please?

I would like to sell this necklace but can't remember its original description and the online store where I got it no longer carries it so I can't look it up that way. Blue Chalcedony comes to mind, ...
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0answers
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Can someone help me to identify this rock/mineral?

This is a small piece of a bigger chunk (about 9kgs). Someone told me it might be meteorite since its heavy for its size and has shiny particles. Others told me it might me an iron ore (magnetite). ...
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1answer
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What could this dark brown stone with a white streak found in Romania be?

We found this in Romania, far away from water basins.
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Melting point of minerals

Looking at this website, I can see the melting point of the following minerals: http://hyperphysics.phy-astr.gsu.edu/hbase/Geophys/meltrock.html Apparently at a temperature of 1200 °C, all the ...
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1answer
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Why is streak different from color?

Many minerals have a streak that's surprisingly different from it's outward color. Why is this? What causes the optical properties to change if the mineral is powdered? Thanks!
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3answers
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Help! Can anyone identify this deep blue rock, quartz, crystal thing from Washington?

I was like 10 waiting for my dad to get off work. He was a surveyor and brought this blue rock thing with him for me when he got off. He said they were surveying and his friend took a pickax to a rock ...
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1answer
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What are the cubic formations found inside Larimar gemstones?

I recently noticed what appears to be common cubic formations just beneath the surface of Pectolite (Larimar) gemstones. They quite resemble transparent sugar sprinkles. Each formation isn't perfectly ...
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1answer
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Difference between pyrite oxidation and dissolution

I've seen papers use oxidation and dissolution of pyrite. Are these two processes the same? I was always under the impression that pyrite does not dissolve easily. What is the difference between ...
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2answers
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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
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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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0answers
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Pyrite oxidation

How much pyrite has to be oxidized to produce a sulfate concentration of 15 mM? If the solution initially has a pH of 8, roughly what would the pH drop to if there is no buffering of acidity?
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1answer
111 views

Is this quartz crystal or something else?

I found this stone on the way. It looks as same as in the attached photo. Some say it's quartz crystal and some say it's something else. Can anyone help me out?
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1answer
280 views

Saturation Index clarification

I have a problem with my project and I was hoping I would find some clarification. I did some modeling with phreeqc to calculate saturation indices and found that calcite was saturated in an ...
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2answers
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Sulfate salts of magnesium and sodium

What concentrations of magnesium, sodium and sulfate are needed to precipitate solid MgSO4 and Na2SO4 (let's say evaporation is occurring in a system) I'm assuming probably really high because they ...
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1answer
191 views

What kind of stone is on this photo

Does anybody know what kind of stone this is? Thanks alot in advance Wolfgang Adamec
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1answer
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Mineral Identification

I have a green, moderately magnetic, rock with yellow inclusions. The rock is very heavy for its size. What is the most likely minerals in such a rock? Update: Found on the Maine coast. Rock has been ...
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1answer
73 views

Satellites minerals finding capability

Just wondering with the latest satellites currently available, is it possible to locate gold which is buried under 200 ft? what is the maximum depth that satellites can look for such minerals.
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Dolomite and calcite precipitation

In an engineered wetland, there is groundwater flow from an aquifer with a chemical composition that is rich in magnesium, calcium and sulfate. We are finding that the aquifer is consistently ...
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2answers
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Limitations on mineral precipitation from solution

If the solubility constant for a mineral is exceeded and, thermodynamically, a mineral is favored to precipitate in solution, are there any factors that may limit this from happening? Perhaps kinetics?...
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3answers
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Why does Australia have no chrome?

I've been trying to collect resource data about Australia for a few years. Some good reference sites are AustraliaMinerals.gov.au and AustralianMinesAtlas.gov.au Australia seems to be pretty rich in ...
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1answer
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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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3answers
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Dissolved minerals

I have a question that I am confused about. If a mineral (say limestone) was added to a groundwater system, say like an aquifer and is completely dissolved in solution, can it ever be a solid again ...
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1answer
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Is there a table with decomposition temperatures of common minerals?

I am about to perform a Loss On Ignition test on a material I know that contains among on things kaolinite, which will release water at 500 $^oC$. However, I tried finding a table with decomposition ...
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0answers
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What is this orange/brown crystalline stone that I found near a mining city in the Philippines?

I found this light colored orange rock with white parts on the road in the Compostela Valley area of the Philippines. The back of this stone has a rough surface and is not shiny. Still, there are ...
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1answer
211 views

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

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

Why does halite have a cubic crystal

Why does mineral halite has a cubic crystal ? Is this a result of the way by which sodium ions and chloride ions are held together ? And what is the relation between the cubic crystal of halite and ...
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1answer
108 views

Rock ID: Opaque Glassy Gem with Unknown Location

I would like to learn more about this rock that I have come to inherit. It resembles a quartz, and after reading about this mineral I am curious if it is a milky Quartz. Anything you can teach me ...