Showing posts with label gold. Show all posts
Showing posts with label gold. Show all posts

Saturday, January 30, 2021

Pigment Palaver: YInMn Blue

Way back in the first post in this series, I mentioned I was inspired to start it by the discovery of YInMn Blue, or Oregon Blue. It actually wasn't commercially available yet back in 2019, but it's finally been cleared for consumer use and went on sale just recently. This site is selling it as part of the Matisse line of acrylics by Australian company Derivan, which incidentally is the brand I've gotten most of my paint from. (Though Derivan's own website, oddly, isn't listing it yet.) YInMn Blue is notable as the first new inorganic blue pigment discovered in quite some time (I've seen conflicting reports on what the most recent previous inorganic blue pigment—Prussian Blue or Manganese Blue—is, but it seems like it's been at least a hundred years since the last one was discovered.)

You might notice, if you followed the link, that this is a very expensive paint. It's currently going for $179.40 for a 40 ml tube, or $4.49/ml. Given that the company is located in Maine, I'm assuming that's in US dollars, so at the time of writing that'd be $5.87/ml AUD. Normally the Matisse Structure Formula line comes in 75 ml tubes in seven tiers of pricing ranging from $10.75 to $38.95, so that's $0.14 to $0.52 per milliliter. Yes, this paint is more than ten times more expensive than standard paint pricing.

To understand why, we have to turn to the name. The name YInMn Blue comes from the chemical formula of the pigment in this paint: yttrium-indium-manganese oxide. (It's also called Oregon Blue, since it was discovered at Oregon State University in 2009.) From what I've read, indium is the main factor in the cost, being a rather rare element (comparable to silver), though the production of the pigment might also be a factor, as it requires heating the oxides of the three elements together at about 1,200 °C (2,200 °F). (Manganese is quite common, and while yttrium is of perhaps middling rarity it's still more common than indium.)

While the prohibitive cost of YInMn Blue means I regrettably won't be able to get my hands on any to try it out any time soon, it's interesting to reflect on the historic costs of painting. While even the costs I noted above will add up over time, we're currently living in the best time ever for pigment costs. Modern chemistry has rendered pigment-making easier and cheaper than ever before in history. As an example, the pigment ultramarine used to be made of crushed-up lapis-lazuli, mined in Afghanistan and imported to Europe. Because of the labor involved, it literally cost more than its weight in gold in the Middle Ages. (Which is why it gets used so sparingly in famous Renaissance paintings!) The gold price listed for today in AUD is $77.77 per gram; multiply by gold's density of 19.3 g/ml to get a cost of $1,500.96/ml. By that metric, YInMn Blue paint is still 256 times less expensive than gold by volume. Unfortunately I don't know the density of YInMn Blue pigment so I can't compare them by weight (which would make the most sense), so comparing by volume, which is how paint is sold, will have to do.

Oh, and the ultramarine that used to be so expensive? We can now produce the relevant molecule synthetically, and Derivan has it listed as a Series 2 (i.e., second-cheapest) paint at $12.95 a tube, or $0.17/ml. That's almost 8830 times cheaper than gold, showing just how much we artists have to be thankful about in this day and age. (I quite like ultramarine and have used it in several paintings, so I'll probably do a post on it at some point.) Anyway, that's enough for now, and maybe in a few years the price for YInMn Blue will come down too (due to improvements in the manufacturing process or economies of scale) and I'll be able to actually try some. Who knows? A hui hou!

Saturday, June 5, 2010

Burning questions of a Saturday morning.

So there I was lying in bed this morning, still half-asleep, when I got to pondering the fact that I, like the atoms that compose me, am made up of 99.99% empty space. I then idly contemplated the fact that most of this mass was in the nuclei of my atoms, at which point I was seized by a burning desire to find out how much all the electrons in all the atoms of my body put together weighed.


I know that last I checked, I had a mass of approximately 60 kg (my weight is left as an exercise for the reader), and a little searching on the 'net produced a table with the percent-by-mass composition of an average person. Starting with the first entry in the list, I have around \(61.35\text{%}\cdot 60\ \text{kg} = 36.81\ \text{kg}\) of oxygen in me. That's 36,810 grams of oxygen. A mole of oxygen being 16.00 grams, that's almost exactly 2,300 moles of oxygen in me.

(A mole, in chemistry, is simply a very large number \(-\ 6.022\times10^{23}\), to be exact. The conversion between grams and moles is pretty easy; if you have an amount of a substance equal in grams to the atomic weight of one atom (or molecule) of that substance, you have one mole of that substance, i.e., \(6.022\times10^{23}\) atoms (or molecules) of the substance. Since the atomic weight of oxygen is 16.00 atomic mass units, one mole of oxygen is 16.00 grams of oxygen. One more of oxygen at \(0^\circ\)C and normal atmospheric pressure would occupy about 22.4 liters, or just under 6 gallons.)

Now, each oxygen atom comes with 8 electrons in tow, \(8\) electrons \(\times\) \(2,300\) moles \(\times\) \(6.022\times10^{23}=1.11\times10^{28}\) electrons.

That...is a very large number. (11.1 billion billion billion).

And that's just the first element on the list! (Although, by virtue of its nature, it is likely to provide the largest number of electrons.) Next up is carbon, which, at 22.83%, comprises 13.70 kg of me. Dividing by 12.00 grams per mole, and multiplying by 6 electrons to each carbon atom, we arrive at \(3.09\times10^{27}\) electrons from carbon, a factor of 10 less than from oxygen (not surprisingly).

Since the procedure is relatively boring, and quite simple, I will spare you further talk and simply list the amounts in the table below:


oxygen        36.81 kg  \(1.11\times10^{28}\) electrons
carbon        13.70 kg  \(3.09\times10^{27}\) electrons
hydrogen      6.00 kg   \(3.57\times10^{27}\) electrons
nitrogen      1.54 kg   \(4.64\times10^{26}\) electrons
calcium       0.86 kg   \(2.58\times10^{26}\) electrons
phosphorus    670 g     \(1.94\times10^{26}\) electrons
potassium     120 g     \(3.51\times10^{25}\) electrons
sulfur        120 g     \(3.61\times10^{25}\) electrons
sodium        84 g      \(2.42\times10^{25}\) electrons
chlorine      84 g      \(2.43\times10^{25}\) electrons
magnesium     18 g      \(5.35\times10^{24}\) electrons
iron          6.0 g     \(1.68\times10^{24}\) electrons
fluorine      2.4 g     \(6.85\times10^{23}\) electrons
zinc          1.8 g     \(5.00\times10^{23}\) electrons
silicon       0.60 g    \(1.80\times10^{23}\) electrons
rubidium      0.60 g    \(1.56\times10^{23}\) electrons
strontium     0.30 g    \(7.84\times10^{22}\) electrons
bromine       0.24 g    \(6.33\times10^{22}\) electrons
lead          0.12 g    \(2.86\times10^{22}\) electrons
copper        0.06 g    \(1.65\times10^{22}\) electrons
aluminum      60 mg     \(1.74\times10^{22}\) electrons
cadmium       60 mg     \(1.54\times10^{22}\) electrons
cerium        60 mg     \(1.50\times10^{22}\) electrons
barium        18 mg     \(4.42\times10^{21}\) electrons
iodine        18 mg     \(4.53\times10^{21}\) electrons
tin           18 mg     \(4.57\times10^{21}\) electrons
titanium      18 mg     \(4.98\times10^{21}\) electrons
boron         18 mg     \(5.01\times10^{21}\) electrons
nickel        12 mg     \(3.45\times10^{21}\) electrons
selenium      12 mg     \(3.11\times10^{21}\) electrons
chromium      12 mg     \(3.34\times10^{21}\) electrons
manganese     12 mg     \(3.29\times10^{21}\) electrons
arsenic       6.0 mg    \(1.59\times10^{21}\) electrons
lithium       6.0 mg    \(1.56\times10^{21}\) electrons
cesium        5.4 mg    \(1.35\times10^{21}\) electrons
mercury       5.4 mg    \(1.30\times10^{21}\) electrons
germanium     4.2 mg    \(1.11\times10^{21}\) electrons
molybdenum    4.2 mg    \(1.10\times10^{21}\) electrons
cobalt        2.4 mg    \(6.62\times10^{20}\) electrons
antimony      1.8 mg    \(4.54\times10^{20}\) electrons
silver        1.8 mg    \(4.72\times10^{20}\) electrons
niobium       1.2 mg    \(3.19\times10^{20}\) electrons
zirconium     0.60 mg   \(1.58\times10^{20}\) electrons
lanthanum     0.60 mg   \(1.48\times10^{20}\) electrons
gallium       0.60 mg   \(1.61\times10^{20}\) electrons
tellurium     0.60 mg   \(1.47\times10^{20}\) electrons
yttrium       0.54 mg   \(1.42\times10^{20}\) electrons
bismuth       0.42 mg   \(1.00\times10^{20}\) electrons
thallium      0.42 mg   \(1.00\times10^{20}\) electrons
indium        0.36 mg   \(9.25\times10^{19}\) electrons
gold          0.18 mg   \(4.35\times10^{19}\) electrons
scandium      0.18 mg   \(5.06\times10^{19}\) electrons
tantalum      0.18 mg   \(4.37\times10^{19}\) electrons
vanadium      0.12 mg   \(3.26\times10^{19}\) electrons
thorium       0.060 mg  \(1.40\times10^{19}\) electrons
uranium       60 μg     \(1.40\times10^{19}\) electrons
samarium      42 μg     \(1.04\times10^{19}\) electrons
beryllium     30 μg     \(8.02\times10^{18}\) electrons
tungsten      18 μg     \(4.36\times10^{18}\) electrons


(if you're wondering about the units, conveniently, 0.06 g = 60 mg and 0.06 mg = 60 μg)

If you add all those electrons up, you come up with a total of \(1.88\times10^{28}\) electrons. That's a lot of electrons -- 18.8 billion billion billion, to be exact. But how much mass do they have? And how much do they weigh?

Finding the mass is easy. The mass of an electron is \(9.11\times10^{-31}\) kg so \(1.88\times10^{28}\) of them together have a mass of 17.1 grams, which has a weight of approximately 1/25 of a pound.

Wow. All the electrons in my body make up a measly 0.0000029% of my mass. Everything else is concentrated in the nuclei of my atoms. Wild, huh?