What is Fool's Gold?

this video has been sponsored by Nord VPN right now they're offering 75% off 3 year plans as well as one month free which you can get by going to Nord VPN comm / nyle rad as a kid I can sometimes remember looking through dirt and finding little bits that looked almost like gold and almost every time I would get really excited thinking that I was rich or something only to be quickly shut down and told that it was worthless fool's gold at the time I kind of just accepted that answer and I threw away what I had found without really questioning much what I didn't know though was that despite it being way less valuable than gold it was still a really interesting compound the mineral name for fool's gold is pyrite or iron pyrite and its chemical name is iron disulfide it's chemical formula is pretty simple just FES 2 but what makes it really cool is the different ways that it can crystallize the appearance that it ultimately takes on will depend heavily on the environment that it was formed in some important factors that affected are things like purity time pressure and temperature for example pirate from a certain region in Spain tends to form these oddly perfect looking cubes which honestly still kind of look fake to me their size and distribution can also vary quite a bit and some crystals can get really big like this one the base unit cell that builds the pyrite crystal is cubic and under these circumstances the macroscopic crystal that formed was cubic as well however impurities and the other conditions that I mentioned earlier can alter how these units build on each other and it can affect the final appearance so depending on where you are in the world and what the geological conditions are in that place it can look quite different for this video I'm gonna be focusing on pyrite but I did want to mention that it is possible for the iron disulfide to have a non cubic unit cell it can instead be something called ortho rhombic and when this happens it forms a different mineral called marcasite this one's a lot more brittle though less stable and has a different color in any case now that we know a bit about what fool's gold is in general I want to dive a bit more into its physical and chemical properties so to start off just in appearance and feel I think it's really similar to metal and color wise it can be close to that of gold and it's also often found in the same area as gold so it's not surprising that they can sometimes get mixed up the biggest difference though is that gold is never found as these sharp and highly ordered structures and it's usually just found as an amorphous chunk like this and another major difference is that gold is really soft and malleable whereas pyrite is really hard and brittle so if it's hit with something like a hammer the pirate would shatter into pieces whereas the gold would just get flattened also in terms of its density it's only around 5 grams per cubic centimeter whereas gold is about 19.3 with small quantities it might be hard to tell but once you get a decent amount of the pyrite the weight difference is pretty obvious so when a big chunk is found it's relatively easy to tell a difference and it's only really an issue when you have lots of small bits for example here in a clip that I found on YouTube it really does look like gold however this was only because the really shiny pyrite was reflecting a lot of the light from the Sun and making it hard to tell its color once he moved to the shade though the brassy yellow color of the pyrite became quite evident but the color of the gold stayed the same his other simple test was based on the fact like I mentioned before that the density of pyrite is way less than that of gold just by gently swishing around the water the heavier gold is able to stay put but the lighter pyrite is moved around from its overall metallic and shiny look a lot of people would think that it's conductive and well they're right it kind of is it's not nearly as conductive as a proper metal though and it's classified as a semiconductor in general semiconductor materials are used pretty extensively in the electronics industry and it has been suggested that pyrite might have some use there as well currently I think the major use of it related to things that are electronic is in non-rechargeable energizer lithium batteries in this battery one of the electrodes is the lithium itself and the other one is made by coating iron disulfide on a thin layer of aluminum okay so now for the fun part where I get to play around with it and learn more about its chemical properties it would have been insane to sacrifice my really nice cube so instead I bought a bunch of ugly ones from eBay I really don't remember exactly how much it cost but it was quite cheap and probably only around $20 for the whole bag of them for the first test I just put a small amount of concentrated hydrochloric acid on one of the pieces I let it sit there for a few minutes but it didn't look like much was happening there should have been a reaction going on but I just think it's really slow the iron disulfide is fes2 but I thought that it might react faster if I converted it to just FES this can be done pretty easily by just heating the pyrite to its decomposition temperature which starts at around 540 C to do this I just carefully shot it with a blowtorch until it looked like the surface was turning black some pieces of pyrite also started cracking off but I'll talk about that in a bit when it cooled down I added the HCL again and the effect was very subtle but it was there like last time I left it for a few minutes and when I removed it almost all of the blackness had disappeared the HCL had also taken on a yellow color which you can see on the paper towel so the major thing that happened here was a reaction between the black iron sulphide that I made and the hydrochloric acid dis led to the formation of iron ii chloride as well as hydrogen sulfide gas the amount that was reacting here was so little though that it wasn't really possible to see any gas coming off however I wanted the effect to be much clearer so I decided to try heating the pyrite more and to convert as much as I could to the FES initially it looked decent and the whole surface was turning black but then suddenly pieces of it started to shoot off I'm not a hundred percent sure what caused this but I think it is a direct result of the decomposition of the iron disulfide in order for it to break down to FES it needs to kick off a sulphur it's fine if this happens on the surface of it because the sulphur just boils off and then burns in the air to make sulfur dioxide however if this happens in the cube there's no place for the sulfur gas to go so I imagine that it starts building up pressure and it eventually gets to a breaking point to a certain extent there's also probably some water mixed into the mineral which also can cause it to explode I continued heating the large piece that remained and initially some pieces did come off of it but eventually it stopped I'm not exactly sure why it stopped breaking apart but I'm assuming that it was somehow able to release some of the gas pressure I kept heating it until most of it had become red-hot and then I let it cool down as it cooled the surface of it slowly got oxidized by oxygen in the air to make what I assumed was red iron 3 oxide when it eventually got to room temperature I thought that it was pretty interesting because it didn't look like the fool's gold at all anymore there was absolutely no gold as yellow color left and it was all just black in red like I just said I think the red stuff was iron 3 oxide but I'm not sure if the black stuff was FES or iron to oxide I tried testing it again by just adding some hydrochloric acid to the surface of it and it kind of just soaked it up if you recall from before though when I tried this with the intact pyrite the acid just sat there so apparently as it decomposed it got a lot more porous I broke it apart with a hammer and what I thought was cool was that it was possible to see all the different layers on the outside was the fully reacted and oxidized stuff but then right underneath it was a layer of black FES then just below that was the still fully intact FES 2 I really thought that the heat penetrated much deeper but apparently it didn't on to this I tried adding the hydrochloric acid again and it worked a bit better it was possible to see a small amount of bubbling but it still wasn't as good as I would have liked it to be to get it to react vigorously I would need to convert a lot more to the FES and to do this I first had to crush it up this really isn't very hard to do though because the pyrite is actually quite brittle so I just added some of it to a mortar and started bashing it this was what I had after a few minutes and I probably could have crushed it a bit more but I figured this was good enough this was all added to a test tube and I did my best to flush it with nitrogen then just like all the other times I blasted it with a blowtorch the reason I used the nitrogen was that I hoped without any oxygen present the sulphur would be able to come off and knock it immediately converted to sulfur dioxide after only heating it a bit it all started turning black and I could see that there was a gas being released from the powder because of the background it was hard to see but there was also a white vapor that had filled the tube at the time it didn't occur for me to test it but it was almost definitely sulfur maybe along with a bit of water vapor what I think is cool is that industrially pyrite is used in a very similar way to this to generate elemental sulphur depending on the purpose the sulfur can be kept as is or can also be converted to sulfur dioxide for the paper industry or even to sulfur trioxide to make sulfuric acid when I felt like most of it had converted to FES I stopped heating it and I let it cool I probably should have refilled the tube with nitrogen though because as it cooled the surface was oxidized and it turned red I figured this was fine because most of it was still black but then I mix things and saw there was still a whole bunch of pyrite I apparently had the same issue as before where it only really converted the stuff on the outside and the stuff in the centre was more or less intact this time though I thought I still made more than enough so I continued on with the testing when I got to room temperature I dumped it all onto a dish and it honestly kind of looked the same nonetheless I took a small sample of it and I placed it onto another dish and tried adding hydrochloric acid again this time the reaction was way more vigorous and a gas was definitely being produced hydrogen sulfide is extremely potent and even in small quantities it smells like rotten eggs so a very simple test for it is technically just to try and smell it this was all done in my fume hood though which apparently worked quite well because I didn't smell anything the only real way for me to smell it would be to bend over and to get really close to it the problem with this though is that hydrogen sulfide is also super toxic around the same level as cyanide gas so I wasn't too excited about trying to take a breath of it the much smarter thing is to instead use test strips these are made pretty easily by soaking paper in a solution of lead acetate and then letting it dry now if I was in fact making hydrogen sulfide then the lead acetate on these strips should be able to react with it to make black a lead sulphide and when I did this that was exactly what happened I was making the hydrogen sulfite here mostly as a demo but in general it is a useful chemical in the lab it's usually produced the same way where a strong acid is reacted with iron sulfide however the iron sulphide is rarely made from pyrite and it's usually either purchased or made directly by reacting iron and sulfur powder it leads to an extremely exothermic reaction and this is a clip from one of the first videos that I ever posted to this channel the videos that I made back then were totally different but if you're interested in checking it out there's a link in the description in any case I think that's about it pyrite might not be as nearly as valuable as actual gold but I think it has enough of its own unique properties and uses that it more than makes up for this and honestly I think the cheap price is actually a good thing because it means that most people can buy it relatively easily for example I think the large cube sample that I have is one of the coolest things that I own but it only cost me something around $100 in Canadian dollars that's about two grams of gold which is not only not very much but also nothing really impressive to look at in any case this was the first video that I did on a mineral I had a lot of fun doing it I definitely plan to do this again with another mineral so in the comments let me know what you'd like to see I ended up getting really behind schedule editing this video so I'm probably gonna be posting it from the airport on my way to Japan for vacation to do this though I'll have to connect to the public Airport Wi-Fi which isn't really secure and kind of makes me nervous however luckily services like Nord VPN exist which allow me to keep my data safe by encrypting everything that's sent and received by my computer this way I can log into all my accounts or even buy things with my credit card without worrying about getting my info or passwords stolen on top of this though there are a whole bunch of other benefits of Nord VPN for example it has a built-in add and malware blocker and it also anonymizes you on the internet making it difficult to track or spy on your activity what I especially like is that they have a super easy to use app that works on all mobile devices as well as laptops and desktops all I need to do is just click one button and it's done automatically there is also the option to do it manually though and you can choose from one of their over 5,000 servers around the world so with that being said I've been using Nord VPN for about a year now and I highly recommend it also right now they're offering a great deal that gives you 75% off their three-year plan as well as one extra free month you can get this by going to Nord VPN comm slash Nile red or by clicking the link in the description as a sidenote some of you might be wondering why I'm posting the video on the way to Japan and not when I get there my answer to this is kind of simple where a I don't really want to be working on videos once I get there and B I just think it could be fun I'm gonna be having a 14 hour plane ride between Minnesota and Tokyo and I just thought that it could be interesting to buy Wi-Fi and to answer your comments from the air as usual a big things goes out to all my supporters on patreon everyone who supports me can see my videos at least 24 hours before I post them to YouTube also everyone on patreon can directly message me and if you support me with five dollars or more you'll get your name at the end like you see here [Music]

Channel: NileRed

Views: 2,156,986

Rating: 4.9247942 out of 5

Keywords: nile, red, science, chemistry, pyrite, fools gold, gold, iron pyrite, mineral, mineral series, vpn, vpn for android, free the internet, vpn network, vpn client, nilered

Id: Y8qEA291Fws

Length: 16min 19sec (979 seconds)

Published: Sat Nov 10 2018