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Questions tagged [mineralogy]

questions relating to the scientific study and identification of minerals.

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1answer
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Is this a rock with metal or gold?

I found these really hard rock while i was excavating. It caught my attention the different colors.
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1answer
16 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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0answers
22 views

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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1answer
37 views

Please identify- no origin known but given to me by a geologist

A very dear man who love his job as a geologist gave this to me. He’s been all over the country so I have no idea where he may have picked it up
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0answers
30 views

What is this Stone

I found this stone in my father's old stuff. I tried to search online for about it but I don't know what is it. It looks to be a rare stone. Can someone identify it?
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1answer
70 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
26 views

A chemical formation or constructed by microorganisms?

This mineral formation was at the side of a fresh water canal in Gürpınar, Van, Turkey. It was dug out from the bottom of the canal. It is very brittle. I know that the natural water sources in the ...
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0answers
49 views

What are the name of these stones?

There are some kind of stone, I collected them and I want to be sure of their identification.
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2answers
90 views

Please help identify this! Rock? Glass? Crystal? It's big and very heavy

About 1.5 feet tall, 1 foot deep and 2 foot wide. Very heavy and very hard. I will get a better picture posted asap. You can read a newspaper thru it. Was left to me by my uncle years ago but never ...
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2answers
78 views

Is this petrified wood or just “some rock”?

I was gifted this and have no idea what it is and was to embarrassed to ask, so here I am.
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40 views

Can you help me identify my rock?

I found this rock in my yard. Can someone please identify it for me? I’m not sure if you can see the blue hue on the rock in the picture! (https://i.stack.imgur.com/cuklH.jpg)
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0answers
17 views

How do I Interpreted EDX Result?

I am new for SEM-EDX but I want to learn. In the EDX data result, there are Wt % and at % from every element (for Example if : Wt % C 14.16, O 51.22, Al 2.22, Si 30.64, Fe 1.75 and At% C 21.11, O 57....
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15 views

How does chalcedony containing quarts and mogánite form?

I just learned that the cryptocrystalline form of silica, chalcedony, usually contains 1-20% of the monoclinic $\ce{SiO_2}$ mineral mogánite as well as the much more common hexagonal quartz. With time ...
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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
116 views

Are these obsidian snowflakes?

I'm not sure if these are obsidian snowflakes: I found it near a river, hardness is 4 to 5, it has a wax lustre when pre-polished. The 'flakes' in the matrix are raised and gray. Pre-polished side ...
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1answer
36 views

What exactly are enantiotropic and monotropic polymorphic transitions?

Recently, I've been studying the subject of polymorphism and met two important concepts, the monotropic and enantiotropic polymorphic transition types. However, I can't really seem to grasp the ...
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1answer
93 views

What's this? Chess pieces growing spines!

These chess pieces have laid undisturbed for a long time (15-20 years?). In this time, they seem to have grown clear/white, spiny, long crystals. I'm wondering if they are dangerous, but also curious ...
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1answer
100 views

Is this deep green calcite, green gneiss stone?

The site where it is found is characterized by schist, quartz and gneis, but also other species of rock. This is a scissors 2 cm semi transparent, vitreous luster, hard scale 6.5 - 7 ... I will post ...
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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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1answer
83 views

Why would CaO be more finely spread than K2O in Granodiorite?

I recently interpreted some XRF data on samples of a granodiorite which were classified under three different types of physical characteristics: very little, mild and significant levels of weathering. ...
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1answer
70 views

Can you help me identifying this beige/brown rock?

I found this stone in a box where I keep some memorabilia. Unfortunately I don't know, where it's from, maybe it's from a mountain side in the alpins or from a beach at the mediterranean sea. One side ...
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1answer
114 views

Help identify this brown red mineral?

This was found in my garden today and has me completely stumped. What is it?
2
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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
29 views

Is there any rule of thumb to decide the indentation hardness test?

How to decide whether Brinell Hardness test, Rockwell test or Vicker's test is to be applied as far as grain-size is concerned? Is there any rule of thumb to decide the type of indentation hardness ...
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2answers
97 views

Help identify glowing stone with scarab carving

I found almost no information from searching Google, Someone mentioned it might be Fluorite. I simply don't know where else to look for an answer and so I am asking you. When I was a child, my ...
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0answers
19 views

Detecting the hydrothermal alteration zones?

Is it possible to use remote sensing to determine Hydrothermal alteration zones without resorting to collecting samples from the Area of study?
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1answer
137 views

What kind of light blue stone is this?

My son found this stone on the beach on the island Crete. It was a one of its kind, no other visible stone on the beach was the same. We asked the locals, but they did not know this stone. It's about ...
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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 ...
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5answers
142 views

Which Earth minerals would Moon colonists miss the most?

In my science-based novel, Moon colonists need to return to Earth to collect some rare or absent mineral(s) Ideally, something they could derive from seawater. Which minerals might they be...?
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1answer
473 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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2answers
43 views

Iron-nickel phase in pallasite meteorites

I have recently been learning and researching about meteorite types and classification. Pallasites are mainly composed of a 'solid-solution' of olivine crystals and an iron-nickel alloy. My question ...
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1answer
50 views
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2answers
222 views

What disciplines of science are used in the locating and extraction of mineral resources? [closed]

Im trying to do an assessment but I just can answer this question!
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1answer
130 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
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 ...
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1answer
50 views

The influence of special emissions (possibly coal mining activity) on particulate matters

Based on multiple site sampling of airborne $PM_{2.5}$ and $PM_{10}$ , the elemental concentrations of the trace elements were analyzed. I have found out in the site near surface coal mining zone ...
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0answers
39 views

Chloride and evaporation

I have a layered aquifer with water that contains high concentrations of calcium and sulfate (~400 mg/L Ca2+, ~1300 mg/L SO42-), at 50 cm below ground surface (bgs), 250 cm bgs and 300 cm bgs. The ...
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0answers
25 views

Formation of dolomite

What are the kinetic barriers to dolomite precipitation? Does it precipitate out in solution as quickly as Calcite does?
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35 views

What are the regenerable natural resources?

It may seem stupid question, but I want to know if metals do regenerate? I mean, every time when our metals finish, then will regenerate after millions of years? Or, for how long will it take to be ...
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2answers
62 views

Geological maps of British Columbia

I’ve been doing research into mineral deposits in B.C. I’ve been overlaying old claims maps onto Google Earth maps. Are there any good public maps for metallic minerals for British Columbia online?
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1answer
180 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
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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2answers
129 views

What is serpentinization, in the context of disappearance of surface water on Mars?

The recent paper in Nature The divergent fates of primitive hydrospheric water on Earth and Mars (Nature 552, 391–394 (21 December 2017) doi:10.1038/nature25031) has been linked by many recent news ...
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0answers
42 views

Formation of minerals from decomposition of soil

I was wondering if aerobic decomposition of organic rich soils, also rich in calcium and sulfur, can result in the precipitation of gypsum. My thinking is the decomposition would release the ...
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2answers
89 views

Analyzing composition of a mineral using SEM

If I have a mineral in which I did a SEM analysis on and got the data (elements and their wt% with Std. Dev., MDL, atomic % oxide % and k ratio) how would I go about quantifying the sample's ...
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1answer
154 views

What are these features in the Tombouctou Region?

I’ve recently been very interested in globe-trotting via Google Earth. At first I was using it to plan out hikes to possible mineral deposits locally, or potential fossils/ archeology sites. However I ...
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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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1answer
205 views

Gypsum saturation index

I did some geochemical modelling and found groundwater samples I have are saturated with respect to the mineral gypsum. I need some help with interpretation, more information is given below. The ...
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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 ...
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1answer
40 views

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 ...