27 votes
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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 ...
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26 votes
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Why is sand, sand; and why is glass, glass; While both mainly contain Silicon Dioxide?

Is it crystallization? You are correct. The main difference is that sand is crystalline and glass is not—it is amorphous. The main component (> 95%) of common yellow sand is quartz (the mineral ...
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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 ...
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18 votes
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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,...
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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 ,...
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11 votes
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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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11 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 ...
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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 ...
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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-...
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8 votes

Structure of Ca2B6O11

1) Oxygen CAN form 3 or 4 bonds. The most common example is $\ce{H3O+}$ ion This form of bonding is critical to understand basic nature of ammonia solutions, so for exact description of it look that ...
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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 ...
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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 ...
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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 ...
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7 votes

How can I determine the chemical composition of local rocks and minerals?

Let's talk about rocks. The art and science of getting useful things from rocks is one of the oldest in human civilization. All of the example products you mention (gunpowder, petroleum, silica, and ...
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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 "$\...
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6 votes
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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 ...
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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 ...
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5 votes
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Can acid mine drainage form acid rain?

I don't think acid rain formation from liquid acid mine drainage is very likely. The reason is that in acid rock drainage (a.k.a. acid mine drainage or AMD), the acidity is caused by sulfuric acid. ...
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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 ...
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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 ...
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  • 6,755
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 ...
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5 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 ...
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5 votes
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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 ...
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5 votes
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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 ...
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5 votes
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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 ...
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5 votes
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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. ...
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5 votes
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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 ...
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4 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 ...
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  • 41
4 votes
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Chemicals to clean natural stones

Removing all of the debris from the stones without damaging them can be difficult, the following is what I've done in the past to clean geodes with debris and deposits. Your mileage may vary, ...
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