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Questions tagged [minerals]

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Help Identifying this Mineral?

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
36 views

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
71 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
34 views

Can anyone help identify this? Or point me in a direction of someone who could

Can anyone help identify? It's crystalline structure is non geometric transparent to light milky (white/purple area) clarity the green color appears gritty and solid like suspended inside the crystal. ...
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0answers
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+50

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 ...
3
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1answer
43 views

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
91 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 ...
4
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1answer
48 views

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
55 views

Identify this transparent brown rock

t The rocks are pretty small they are dark brown and comoleyelybsee through.
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1answer
99 views

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
38 views

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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0answers
46 views

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
74 views

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
52 views

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
65 views

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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2answers
153 views

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
53 views

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
170 views

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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0answers
52 views

I need help identifying this pinkish rock found in Morocco

Found in Morocco, the oriental region, exactly in Oujda, near the Algerian border in the deep woods with another one with the same shape and colors. Not heavy. Feels very smooth. 3 colors : White - ...
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0answers
26 views

Alluvial diamonds deposits

What are the minerals that are usually related with the presence of alluvial diamonds deposits. I need to know which minerals are often used for tracing/tracking the presence of rough diamonds on ...
5
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1answer
85 views

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 ...
5
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1answer
42 views

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 ...
3
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0answers
150 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
131 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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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
100 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?
4
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1answer
181 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 ...
5
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2answers
47 views

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
183 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
96 views

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
71 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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0answers
68 views

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
54 views

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
85 views

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 ...
3
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1answer
76 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 ...
3
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3answers
513 views

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
169 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!
4
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2answers
88 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 ...
0
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1answer
213 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 ...
2
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1answer
99 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 ...
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2answers
470 views

Please help me identify this stone

I got a stone from my grandfather and wanted to know more about it. Can anyone please guide me in what this stone is called. And does it have any value in price
4
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1answer
65 views

What causes this white coloration of the ground in Gilf-Kebir?

It seems, these white blotches are reflective enough that they caused oversaturation of a spot of image taken from a satellite at the L1 lagrangian point (click to open at max resolution, the purple ...
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2answers
84 views

Pinkish quartz like. Help identifying and if it is worth anything?

I recently purchased a home, in the fireplace surround that I tore down were several rocks (quartz) that I thought were unique. I am looking for identification help and if they were worth anything. ...
16
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1answer
1k views

What are these metallic nodules that were found at low tide on the UK south coast?

Smooth spherical crystalline metal nodules Outside and inside surface does not scratch with a knife blade Inside lustre brassy, radially striated metallic crystals radiating from a lumpy centre at the ...
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2answers
607 views

Why are most minerals so rare?

There are 4,660 known minerals, so why are most of them so rare? Is it to do with the structure of minerals?
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1answer
241 views

Could you please identify this rock for me

I found this rock several days ago and think it looks like RUBY ! Could you please help me to recognize it ?
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1answer
86 views

What is this bronze colored rock from Ohio?

I found this rock in a stream near Toledo, Ohio.
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2answers
992 views

Are there any areas on Earth with purplish-colored soil/sand/rock/land?

This sort of comes from my related question, but only sort of. Are there any areas on Earth with purplish-colored soil? The purple tint would come from some mineral, perhaps deposited by rivers or ...