Quaxo76

What? Really? Bromine corrodes GLASS?!? That puts an end to any hope I had of keeping it... I have no means of re-ampouling anything, nor any friends who can do that, and besides, if Br2 gets through the glass, I believe in the long term resin doesn't have a chance...

I'm trying to collect all the (non highly-radioactive) elements of the periodic table, in pure form. I already have about 65, and I just received 50g of iodine, and will soon receive 5ml of bromine. I'm having problems with storage of iodine though, and I suppose bromine will be even worse... The iodine arrived in a glass container with a plastic/rubbery seal, and it was already slightly corroded. I put it in a borosilicate glass vial with a screw-cap with silicone seal, but it turned yellow pretty soon. Iodine smell didn't come out but I guess it was just a matter of time. Then somebody told me to store it in a glass vial with glass cap (the ones with a "ground" glass at the interface between vial and cap, I don't know the English name), putting some silicon grease between bottle and cap... I did that, but after a few hours the grease layer between cap and vial started turning purple, and after 4-5 days all the grease is purple, and I can smell iodine again. Now the lady at the shop where I buy lab supplies, sold me a glass vial with a plastic screw-cap but with a teflon seal. She said that teflon can indefinitely store both iodine and bromine, and that that's how they store them. Is this true? Can I use the teflon caps? If not, is there any other way? What about a tight, high-quality glass vial/glass cap? Maybe with some teflon inbetween? (I don't have the means to make a sealed glass vial as I don't have a hot flame). Thank you in advance, Cristian

OK, I managed to find 8 small (3cm) crystals of pyrite. All of them are nice, shiny and without any "extraneous" marking. And cheap, at about $1 each. I have been less lucky in locating antimonite. I only found a small crystal, same size as the pyrites, for $20. But I bought two crystals of galena (PbS). So I setup 2 small sealed boxes, one with galena and pyrite, and one with pyrite and antimonite. I would like to find other antimonite crystals, to experiment with adding a small piece of metallic copper, and varying humidity and temperature in the boxes... We'll see what happens. Too bad it'll be a "long-term" experiment! But I REEEALLY would like to know what's happening here... Cristian

Hmm, so you think the black stuff on the pyrite is made of iron and sulfur... so, would some sulfur have left the pyrite leaving the black stuff behind? But that's so strange, as the new stuff on the pyrite looks *exactly* like the antimonite! Same color, same crystal shape, same "glossy" look... OR there's another possibility: I'm not an mineralogy expert, and though those minerals look very much like antimonite and pyrite, there's a chance that the sellers were (unwillingly?) wrong, and they're totally different things... Is there any way to check for sure? Or even to check if the stuff on the pyrite is the same stuff of the other sample?

So you think that the antimonite's molecules are dissociating? But why? What's a "displacement" exactly? And why does then the atomic element only crystallize in a single part of the pyrite? And what happens to the sulfur, does it remain on the surface of the antimonite? Whew... lots of questions...

The box has absolutely no air circulation (the lid has a tight fit). I can't rule out magnetic fields totally, but I tried "scanning" the area with a sensitive compass, and it didn't move. Same for electric fields: I can't rule them out, but there are no electric appliances or hidden wires nearby. I also tested for radioactivity (just in case) but the only slightly active rock nearby is a piece of lava, but it's really mild. The samples shelf though is a couple of feet over a radiator. So, in the winters, there has been some thermal cycling. I don't know if the copper is simply oxidized. I've seen a lot of oxidized copper, and usually the oxide "sticks" to the copper. Here instead, it's really like black soot, if you touch it ever so gently the "soot" sticks to the finger, and the copper below is exposed (and it's shiny). Do you think the new crystals are antimonite, or pure elemental antimony? The photos don't show it clearly, but it has areas that look pitch black and glassy/oily. Fascinating stuff... I think I'll try to find some more samples and set up a few long-term boxes with varying conditions...

Here are the photos! In the first, you can see the whole box, and you can see how the rocks were laid out. You can also see the copper crystal, with the blackened tips. The black over the copper crystal isn't hard, like an oxide layer: it looks like soot, and sticks to the fingers when you touch it. I had never seen copper do anything like that before! All this thing keeps looking weirder and weirder... Cristian

Hello, Thank you for your reply! I know that several years is a long time, but I had no idea that natural minerals could sublimate so quickly - after all that rock must have formed ages ago... But on a more careful check, I saw that it's "degenerating": it now has cracks it didn't have before, and it lost some "crumbs". The environment isn't too humid, as it's stored in my room, in a closed box. But I forgot to add something, I wonder if you can make something out of it: in the box there's a third specimen. It's very small. It's a 1.5 cm long electrolytic crystal of copper. I made it from a solution of CuSO4, and it's been in the box with the other specimens for all the time. It's quite farther away from antimonite than pyrite. And instead of being red (or brownish or green, like I would have expected after years) it has the top part of the top crystals (and only those parts) turned pitch black. The rest of the specimen is brown-red as expected. On this copper crystal, I can't see any acicular crystal like I can see on the pyrite sample. What could that be? Copper oxide? Antimony? Iron? I really wonder... I would like to be able to speed up the process and set up some controlled environment experiments... As for the photos: now it's night here, I'll take some tomorrow morning with the sunlight and post them ASAP. What size photos can be attached here? Regards, Cristian

Hello, This is my first post here... I've been a lurker for quite some time, but now the time has come to ask my first question! I know this is not a mineralogy forum, but a really strange thing happened and that's definitely something chemistry-related so I thought you might know! It's something I had never heard about before, and Googling about it didn't return anything. So, basically, I have a small but quite varied minerals collection. I keep all my minerals in medium-sized transparent plastic boxes; usually 2 to 5 minerals are placed into a single box. In one of these boxes, there was a large piece of what was told me to be antimonite (Sb2S3) together with a large crystal of pyrite (FeS2). The rocks were not touching, but close to each other (there was a gap of maybe 1cm). They were left to sit there for maybe 4-5 years (many boxes are stacked on top of each other, so it's not easy/convenient to move them often; and besides, they're sealed so no dust gets inside, so there's no need to clean/dust the minerals). But today I was moving things around (to test my specimens for radioactivity) and I noticed the weirdest thing... On an area of approx. 4cm^2 of the pyrite crystal, on the side near the antimonite rock... well... lots of medium-sized crystals of antimonite have grown. What is going on here? Is this normal and maybe expected or what? Are Sb atoms "flying" from antimonite to pyrite to combine with the sulfur there? And if so, why does this happen, and what happens to the iron atoms? Is there a cloud of free Sb atoms flying around inside that box? Please forgive me if this is a stupid question but I couldn't find any info anywhere. I can try to post macro photos if needed. Thank you in advance for any information! Cristian