Turning scrap copper into beautiful crystals | Hacker News Reader

Turning scrap copper into beautiful crystals

crystalverse.com

309 pointsjamesy0ung41 comments

Copper sulfate creeps along the surface of the container I've noticed. I was recently growing some crystals from a kit with my daughter and the blue liquid (which I now believe to be copper sulfate) crept out of the container and started growing on surrounding surfaces which had never been wet. I'd like to learn more about why this happens.

Someone asked about this on Stack Exchange: https://chemistry.stackexchange.com/questions/84704/how-can-...

They never got an answer.

To be clear, the container wasn't disturbed or vibrated excessively. The liquid was never spilled outside the container. In my case, there were 3 plastic cups in a single tray, all connected, and the substance grew out of one cup, down into the bottom of the next cup over, and then started back up the other side of the empty cup which had never had liquid in it. This isn't a residue left over by evaporating liquid. A thin film of this substance grows on surfaces above the highest point the liquid ever reached. Clusters of the stuff started forming a couple inches from the only container that ever contained liquid.

I asked about this just today on Reddit actually: https://www.reddit.com/gallery/u85pwz

Is capillary action not a satisfying enough answer for you?

Capillary action requires narrow channels. Single surface shouldn't work, at least intuitively. Some might argue that any tiny crystal formed creates narrow channels between the crevices, wicking out more of the liquid and speeding up outward crystal growth. But even that is something I came up with off the top of my head, and I wouldn't find it credible without a better source than my shower of thoughts.

This mechanism is mentioned in the Chemistry Stack Exchange question linked by the OP.

> Indeed, capillary effect is enough. New portions of solution get higher and higher up, and deposit crystals to build more capillaries, much like a horde of guys with ladders storming some medieval fortress.

I suspect that the capillary action is started by microscopic scratches in the plastic formed when the plastic cups are removed from the molds they were shaped over. This may explain all or some of the capillary effect.

Should be easy to verify by suspending some surfaces ~1cm away from the side of the container to see if there is any deposition occurring by vapor.

It happens in glass too, as shown in one of the pictures.

Glass can have microscopic scratches that act as capillaries. Somewhat related: I remember one of my undergrad chemistry practicals where we had a supersaturated solution in a test tube. Scratching the inside wall of the tube produced tiny glass shards that induced precipitation of the solution.

I don't know much about chemistry so the two word answer "capillary action" wasn't enough, but now that I see it I will do more research.

Not an answer, but that looks very cool!

Maybe that type of plastic has a rough surface making this happen? Glass is much smoother so maybe this is why it doesn't happen in glass.

I have a master degree in chemistry and during my studies have grown quite a lot of crystals. As a lot of the other posters point out it is due to capillary effects; both formed by the new crystals and by microscopic channels and irregularities in the container.

If crystals didn't 'want' to grow we would often cool the solution down and scratch the bottom of the glass container with a metal spatula.

this sounds like a GREAT science experiment for a kid. "We observed ..." leading to setting up controlled conditions with several variables, some microscopes and other ways to see the motion of the crystals, etc. I originally would have said evaporation, other people suggest capillary action- who knows, you might even get a paper out of it.

What a great example of the Baader-Mainhof-phenomenon [1]. I recently found out how easy it can be to create nice-looking crystals at home, and now it seemingly follows me to reddit and hackernews.

I can heartily recommend this website, especially the different kinds of salt crystals, as they are non-toxic and can therefore be handled by children, if you have any.

I wish there were a proper aggregator of sites like this, Ian's shoelace site and all these other informative websites of different hobbies without the fluff present in reddit and the like.

[1] https://en.m.wikipedia.org/wiki/Frequency_illusion

I’ve been trying to learn about rocks and came across this in lists of deadly rocks: https://en.m.wikipedia.org/wiki/Chalcanthite Which is annoying because even rocks are out to get me. It’s chemical formula is CuSO4·5H2O which reminds me of H2SO4 which is sulphuric acid. The article does contain a warning.

Sadly, hobbyist-level of crystal growth almost always either involves hydrates or, unsurprisingly, water-soluble formations, leaving you with delicate structures of low Mohs hardness or pieces that require specific humidity ranges. It would be interesting if it were otherwise, because you could shape the growth of items that were amenable to handling, as well as embedding smaller items in them, perhaps making for things that were both attractive and functional.

Is it cheating to just coat the crystal in resin or paint it with clear nail polish?

I suspend mine in jars of mineral oil.

This guy should sell ready made crystal growing kits.

I have no real interest in this. But I really appreciate this mans love of crystal growing and how well he is sharing it with others.

Absolutely brilliant!

On a side note, I must wonder about the semiconductor properties of these and other crystals -- could they be made into transistors or IC's like Silicon is?

Could they have any potential future use in 3D printed electronics?

Well, I don't know what the answers to those questions are, or will be -- but it's something I like to think about...

Anyway, the crystals are absolutely beautiful!

Great article!

Ignoring the crystal part of that, it's interesting how valuable copper has become ($4.68/lb right now). This is making recovery of scrap copper from wires and small motors and transformers quite economical. You can see videos on Youtube about how to make $100K/year recycling copper.

You have to have an economical source of copper though--which is difficult to do ethically.

I'm wondering if it's economical to strip out accessible copper pipes from older homes and replace with PEX.

Material wise? Sure if you do it yourself. Paying someone else to do the work though? Definitely not.

To rephrase: if you do it yourself and accept that you will be compensated less for your time than anyone you could employ to do it.

Have you seen this guy?

"If you ain't burning a hundred pounds of copper wire, and strippin' a hundred more. Where the fuck you at?"

This is my fav video about this topic:

https://bit.ly/3vvSou4

I really can't tell what's satire anymore.

I climbed to the top of the plateau in Cape Breton, NS, Canada. They had comm/sat tower there. It made me laugh when I saw big poster saying something like: "guy wires supporting this mast are not from copper so do not cut and steal those".

[deleted]

Kind notice: I think you may have left your comment in the wrong thread, as the "Managing mental health while running a startup" one is currently adjacent to this one about crystals.

Link: https://news.ycombinator.com/item?id=31106150

Reply on news.ycombinator.com