Questions tagged [mineralogy]

questions relating to the scientific study and identification of minerals.

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1answer
148 views

Is there any mineral identification techniques that works for all minerals?

Are there any Mineral Identification Techniques that work for all minerals(Non-Metallic/Metallic), so that an electronic device could be made to distinguish between all minerals?
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1answer
74 views

Where/how people find minerals

Forever I have seen little shops here and there offer minerals like those crystals and neat shaped rocks of different kinds, turquoise and amethyst and many others and such. But I never really thought ...
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1answer
60 views

Identify these crystals

What are these? They're slightly green around the edges with clear in the center. I'm assuming geodes. But my friend says they could be Ellensburg Blues?
2
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1answer
159 views

Ions & elements, which is the correct terminology to use when discussing chemical compounds in Earth Science?

Different textbooks use different terminologies when discussing the same chemical compounds, for example when discussing the minerals... Elements / Compounds Sulfide minerals consist of metallic ...
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1answer
26 views

Name of majorite endmember $\ce{Mg3(FeSi)Si3O12}$

Does the majorite garnet $\ce{Mg3(FeSi)Si3O12}$ have a name?
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1answer
70 views

An oblique-square-prism crystal?

Does any mineral crystallize in the shape of an oblique square prism? If so, what crystal system (monoclinic, cubic, hexagonal, etc.) would such a mineral fall under?
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1answer
138 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 ...
2
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1answer
166 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 ...
2
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1answer
165 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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1answer
61 views

Did we find cinnabarit?

We searched for cinnabarit in an abandoned mine (Google Maps, in Békásmegyer, Hungary). We collected these samples, but as we are not geologists, we are not sure what we found. Pictures about the ...
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1answer
82 views

Voronoi-like pattern in metal samples

What is this pattern in the samples' surface called and how/why is it formed? I remember having seen a similar pattern in galvanized sheets. Photos of metal samples from Wikimedia Commons (here and ...
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1answer
62 views

What is this translucent and blue vein crystal, 7.5 < Mohs < 9, Lustre: Aventurescence

It looks like quartz, but it has blue veins on the surface that look died. Not all surface scratches are blue though. Hardness: > 6.5. Nail file will not scratch it. > 7 quartz will not scratch it. >...
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1answer
154 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
357 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
439 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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0answers
107 views

Green Rock Identification

This rock was found in the highlands of Scotland in the mountains.It is 2 1/2''x2 1/8''x 1'' it has a density of 2.95 leaves a clear streak weighs 130 grams and a hardness of 6 on Moh's scale.This ...
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33 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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1answer
64 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
128 views

Help identify this brown red mineral?

This was found in my garden today and has me completely stumped. What is it?
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3answers
144 views

Connection between microbes and serpentinite?

Serpentinite belongs to the serpentine group. This group of minerals are metamorphic minerals caused a special process called serpentinization. Serpentinization created serpentinite on the Earth's ...
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2answers
194 views

How are minerals classified?

What exactly is done to classify minerals in Earth Sciences such as Geology? How can it be known if one mineral is the same as another if they should be visually different?
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3answers
102 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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4answers
444 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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2answers
280 views

What type of rock is this found in a common UK stone mix?

Can any one help identify this rock? Found in the UK, found in a common garden stone mix. Hard to drill but breaks with a hammer easily. I'm assuming it's fairly common but can't identify it. ...
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1answer
525 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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3answers
55 views

Pinkish rock with red 'veins'

I found this rock in Smithfield NC. It does scratch glass. A butter knife didn’t scratch it. When you hold it to a light it has an orange glow. It didn’t leave anything on porcelain.
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2answers
39 views

What does the unit cell of petitjeanite look like?

The question in Chemistry SE What is the crystal structure of bismuth oxyhydroxyphosphate (BOHP)? is about a catalyst synthesized by accident. A link in this comment points to the page https://www....
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2answers
81 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
65 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
68 views

I need some help with a Crystal or mineral

I got this crystal. It is 1 inch long. Flat thin crystal. It was on a small rock. Thank you
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1answer
57 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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1answer
71 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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1answer
82 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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2answers
225 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
228 views

Why do manganese nodules have different constitution than sea water?

Analysing the constituents of manganese nodules, we find that the relative proportion of minerals differs from that of the surrounding sea water. Can someone explain to me why the proportion of the ...
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2answers
43 views

Can gemstones be cut into sheets? [closed]

TL;DR: Without lasers, electricity, or otherwise modern tools, could large transparent gems be sliced (like glass window)? So I’m world building. On this planet they have caves with enormous gemstone/...
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1answer
17 views

Does the shear modulus of silicate minerals vary significantly with changes in P and T?

I know that the bulk modulus, K, varies with pressure and temperature for silicate minerals and liquids, but what about the shear modulus? If so, is the change drastic for changes from standard ...
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1answer
598 views

How gold deposits can be formed in Himalayas?

I have heard that gold is found in the water coming out of glaciers in Skardu region of Pakistan. Given that this area is part of Himalaya, what processes could result into ores of gold in this area?...
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1answer
70 views

What type of mineral is this? [closed]

My grandfather found this thing.
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0answers
55 views

Rock ID: black rock found in Central Europe

I'm note sure if it's an anthracite, augite, jet (lignite) or something completely different. I don't know where exactly i found it because it's from my old rock collection. I would appreciate your ...
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0answers
47 views

what type of rock is this? blue/green and brown [closed]

I found this rock while up in the mountains and I have no idea what type of rock it is.
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1answer
117 views

Mineral identification - please help!

I'm currently writing an essay on a mosaic in the British Museum, and am unsure about which stone the frame is constructed from (pictured). I would be most grateful for help identifying it. Thanks! ...
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1answer
79 views

Is this a rock with metal or gold? [closed]

I found these really hard rock while i was excavating. It caught my attention the different colors.
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0answers
37 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
57 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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1answer
38 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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0answers
25 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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0answers
83 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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0answers
213 views

What is solidus and liquidus temperature of granite?

My understanding is that because a rock is composed of variety of minerals, so it does not have fix melting point, rather there is a range below which whole rock is solid and above which whole rock is ...
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84 views

Is it ok to use biology microscope for gemological purpose?

Is it ok to use biology microscope for gemological purpose? What's the difference?