27
votes
Accepted
Will we ever run out of gold, silver, copper and other important conductors?
How long will these reserves last?
Short answer: longer than you think and will outlast me, you, our children and our grandchildren. Possibly last forever.
Long answer: This is a fairly complex ...
- 5,214
23
votes
Commercial chalk for kids composition
I am afraid whoever told you "sulfuric acid carbon" does not know the basic terminology (must be from non-chemistry background). There is no such thing as "sulfuric acid carbon" to begin with. Any ...
- 39.1k
18
votes
Accepted
How is hair tissue mineral analysis performed?
The analytical technique is called inductively coupled plasma optical emission spectroscopy. It was invented by a chemist V. A. Fassel, although it is pure physics. The specimen is digested in an acid,...
- 39.1k
13
votes
Melting point of obsidian
Obsidian
This is a volcanic glass, formed when rhyolitic lavas cool too quickly for crystals to form. From a chemistry point of view, it's a mixture of silicon dioxide, aluminium oxide, with sodium ,...
- 231
12
votes
How is hair tissue mineral analysis performed?
Inductively Coupled Plasma (ICP) based techniques are very common for elemental analysis. The goal of such analyses is to quantify the elements present in a sample. The neat thing about this, in my ...
- 4,703
11
votes
Accepted
What is the oxidation state of copper and iron in chalcopyrite?
A number of papers report that the formal valency states of chalcopyrite are best considered as $\ce{Cu+Fe^3+S2}$, based on various computational and spectroscopic evidence.
References:
Klekovkina, ...
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10
votes
Why is the only natural source of radium compounds uranium minerals?
You can't find primordial radium because it's half life is too small compared to earths age.
Even the radium isotope with the longest half life, $\ce{^{226}Ra}$ has a half life of only 1600 years ...
- 3,075
9
votes
Can olivine be used to make glass?
You could proceed from either end member of the olivine solid series and yield $\ce{SiO2}$ as you suggest.
However, I'd consider mechanisms that have been researched in the course of studying so-...
- 10.6k
9
votes
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Number of bridge oxygen atoms in a silicate mineral
I am answering it to let others know that I have got the satisfactory answer, thanks to andselisk.
Since $\ce{M}$ is divalent and $\ce{M’}$ tetravalent, they exist as $\ce{\overset{2+}{M}}$ and $\ce{\...
- 342
8
votes
How are Uranium and such materials made
Some radioactive materials are made by man, others have been parts of earth's rocks since they were formed
Radioactive materials are not all the same. some are man-made and some have been with us ...
- 35.5k
8
votes
Commercial chalk for kids composition
Rather pure chalk ($\ce{CaCO_3}$) can be found in the subsoil of huge regions of central France. This chalk can be used for writing on blackboard, but it is too soft. You quickly get whitened fingers ...
- 27.1k
8
votes
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Why does calcined feldspar crumble?
You're replicating the natural weathering process of granite.
Granite is a rock comprising the minerals feldspar, quartz, and mica.
There is a continuous solid-solution ternary diagram here that ...
- 10.6k
8
votes
What does the 'S' stand for in base-centered cubic crystals and Bravais lattices?
S also has German origins: seitenflächenzentriert (side face centered).
Reference: International Tables for Crystallography, Volume A, Space Group Symmetry, Fifth Edition, Springer 2005, pg. 748.
One ...
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7
votes
What is chemical formula of Bauxite?
$\ce{Al2O3.nH2O}$ is just a general (and slightly incorrect, see below) way of writing the formulae of the aluminium oxy-hydroxides that occur in bauxites. These are solid minerals, so there is no "$\...
- 5,214
7
votes
Accepted
Why are the rare Earth elements divided into light and heavy categories?
Though scandium and yttrium have lower atomic mass, they fall in the category of HREEs. The classification seems to have something to do with the formation of REE ores. Here is an extract of Wikipedia ...
- 527
6
votes
Can glass be made with anorthite?
In theory, yes it is possible. In practice, not really.
First of all, the anorthite on the moon is never pure anorthite ($\ce{CaAl2Si2O8}$) but rather an anorthite-albite ($\ce{NaAlSi3O8}$) solid ...
- 5,214
6
votes
Accepted
Is iron pyrite dangerous to handle?
Pyrite does not turn into sulfuric acid. You can burn it with oxygen to give iron oxide and $\ce{SO2}$.
$\ce{4 FeS2 + 11 O2 -> 2Fe2O3 + 8 SO2}$
$\ce{SO2}$ with water gives sulfurous acid. To ...
- 12k
6
votes
How is hair tissue mineral analysis performed?
Neutron activation analysis is a technique that can be used for trace mineral quantification in a sample.
You start by irradiating your sample in a small experimental nuclear reactor. These were more ...
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6
votes
How many bonds does oxygen really make in minerals?
This is a human.
Well, sort of.
All right, call it a simplified representation. But at least it shows the arms/legs ratio accurately, you can't deny that.
Now that was about as good as the molecular ...
- 31.1k
5
votes
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How to determine age of stones (and other inorganic matter)?
The question being asked, I believe, is the age of the inscription or statue rather than that of the material from which it is made.
The answer, though, is that it is quite difficult to do on the ...
- 30.5k
5
votes
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Is there any way to refine Feldspar?
Aluminium oxide can be isolated from feldspar by first acid digestion with a mixture of hydrofluoric acid and sulfuric acid (get rid of silicon by formation of silicon tetrafluoride), then digesting ...
- 7,142
5
votes
Strontium is more common than sulfur?
The primary reason for this and other seemingly implausible features of element distribution is this: some elements are concentrated, and some are scattered. Strontium is much like calcium (which is ...
- 31.1k
5
votes
How can I obtain oxygen gas from plagioclase
Yes, I collect oxygen isotope data from plagioclase using the laser flourination method. To liberate the oxygen from the plagioclase, crystals are reacted with purified $\ce{BrF5}$. Then the ...
- 51
5
votes
Accepted
Can olivine be used to make glass?
The previous answer is not really helpful because you would need huge amounts of CO2 which are not available on the moon. You need 2 moles of CO2 to generate 1 moles of SiO2. You simply do not have ...
- 5,214
5
votes
Accepted
Must a sample of a deuterated compound be isotopically pure for kinetic isotope experiments?
There are two approaches to measuring kinetic isotope effects.
One is to have two completely separate, isotopically pure systems, one heavy, and one light. In each system you can measure the rate of ...
- 21.9k
5
votes
Accepted
Is there pure iron in nature?
Fairly pure iron (or iron/nickel alloys) are found in meteoric iron. Some of these are surprisingly corrosion resistant... close to stainless steels. One well-known example is a dagger from ...
- 30.5k
5
votes
Accepted
Some substances appear white when crushed while others do not. Why?
It depends if the substance in bulk is transparent, highly reflective (metallic) or highly absorptive.
Carbon in its graphite allotrope is highly absorptive, and even finely divided is still black.
...
- 30.5k
4
votes
What is the simplest formula for the mineral beryl which contains 5.03% Be, 10.4% Al, 35.5% Si and 53.58% O?
Firstly the "correct" answer seems to be wrong, which is not an uncommon occurrence, so please do not always take answers at the back of books to be correct. Wikipedia lists the formula of beryl as $\...
- 71.1k
4
votes
Does simmering sparkling water change/decrease its mineral composition significantly?
No, simmering sparkling water should have negligible effect on its mineral composition.
You're exactly right that simmering it will drive off the $\ce{CO2}$. This $\ce{CO2}$ leaves as only/exactly $\...
- 17.3k
4
votes
What happens to minerals once you boil off liquid in a water and fat mixture?
Because dietary minerals are predominantly water soluble and not significantly soluble in fats, your first statement is correct; the minerals will not dissolve in the fats as you boil away the water. ...
- 17.4k
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