The Stack Overflow podcast is back! Listen to an interview with our new CEO.

Questions tagged [mineralogy]

questions relating to the scientific study and identification of minerals.

Filter by
Sorted by
Tagged with
2
votes
1answer
83 views

Metallic Balls Found in Sandstone or Mudstone Layer [closed]

Found metallic balls of some type of metal ore surrounded by yellow mudstone the metallic balls crush easily into a fine gray powder. The gray balls are situated between sandstone layers in a soft ...
2
votes
1answer
90 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 ...
2
votes
2answers
137 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?
2
votes
2answers
220 views

Identification of dark red mineral [closed]

Found in a wooded area after being dug up by my dog. Could not find anything similar online so I thought it best to ask those with far more experience. I'm guessing that it could be petrified wood? I ...
2
votes
1answer
792 views

What is the geologic origin of the Bauxite deposit in Bauxite, Arkansas, and could there be more?

Bauxite is an mineral of Aluminum. Despite a general mineral wealth, the USA does not have any major Bauxite deposits, except for one in Arkansas. The mining town was named Bauxite, Arkansas. The ...
2
votes
1answer
83 views

How can a crystal habit be round?

I am confused how hematite can have a "botryoidal" habit when its crystal structure is trigonal, which is an angled structure. How can an angled crystal present itself as rounded? If a botryoidal ...
2
votes
1answer
155 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?
2
votes
1answer
38 views

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

Does the majorite garnet $\ce{Mg3(FeSi)Si3O12}$ have a name?
2
votes
1answer
61 views

Identify these crystals [closed]

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
votes
1answer
169 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 ...
2
votes
1answer
92 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?
2
votes
1answer
140 views

Are these obsidian snowflakes? [closed]

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
votes
1answer
318 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
votes
1answer
172 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 ...
2
votes
1answer
63 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 ...
2
votes
1answer
85 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 ...
2
votes
1answer
71 views

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

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. >...
2
votes
1answer
167 views

Is this deep green calcite, green gneiss stone? [closed]

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 ...
2
votes
1answer
387 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 ...
2
votes
1answer
507 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 ...
2
votes
0answers
214 views

Green Rock Identification [closed]

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 ...
2
votes
0answers
33 views

Formation of dolomite

What are the kinetic barriers to dolomite precipitation? Does it precipitate out in solution as quickly as Calcite does?
1
vote
1answer
73 views

What kind of purple stone is this? [closed]

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

Help identify this brown red mineral? [closed]

This was found in my garden today and has me completely stumped. What is it?
1
vote
3answers
156 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 ...
1
vote
2answers
219 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?
1
vote
3answers
107 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 ...
1
vote
4answers
529 views

What is this Lake Michigan rock? [closed]

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 ...
1
vote
2answers
331 views

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

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. ...
1
vote
1answer
553 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!
1
vote
3answers
90 views

Pinkish rock with red 'veins' [closed]

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.
1
vote
2answers
41 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....
1
vote
2answers
87 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?...
1
vote
2answers
75 views

Where can I get mineral testing done? [closed]

Where can I send a sample of material to be tested to see exactly what it is? Do you have an address where items can be sent for testing and evaluation? I have a softball size rock that was given to ...
1
vote
1answer
86 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 ...
1
vote
1answer
71 views

I need some help with a Crystal or mineral [closed]

I got this crystal. It is 1 inch long. Flat thin crystal. It was on a small rock. Thank you
1
vote
1answer
61 views

What is this translucent blue-green oblong crystal? [closed]

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 ...
1
vote
1answer
72 views

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

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
1
vote
1answer
84 views

Can you help me identifying this beige/brown rock? [closed]

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 ...
1
vote
2answers
256 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 ...
1
vote
1answer
245 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 ...
1
vote
2answers
49 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/...
1
vote
1answer
18 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 ...
1
vote
1answer
665 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?...
1
vote
1answer
71 views

What type of mineral is this? [closed]

My grandfather found this thing.
1
vote
1answer
76 views

Rock ID: black rock found in Central Europe [closed]

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 ...
1
vote
0answers
53 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.
1
vote
1answer
120 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! ...
1
vote
1answer
88 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.
1
vote
0answers
61 views

Can you help me identify my rock? [closed]

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)