How to grow sodium chloride crystals at home
crystalverse.com
crystalverse.com
On the other hand, being the competitive person who excels in science projects is often a very good predictor for being able to handle the tedium of a scientific lab job.
Even showing a lack of interest in their pointless projects is a life lesson in priorities and individualism.
For example, most of my help was to make sure she took 10 different containers and placed them in different locations around the house to increase the probability of getting a few decent crystals. I discussed redundance with her in the context of explaining why some of her friends were not getting results from their single try. I think that these practical thought patterns are extremely valuable, better than creating a miniature jaded adult...
The point of school is to learn to think + learn to face adversity & failure....
> The trouble is that no one else was able or cared to do it so fast, so the deadline has been slipping for a couple weeks now, with our best crystals going to school and back a few times, getting scratches and broken bits instead of nicely growing undisturbed. A bit discouraging.
The thing is, the "no one cared" is very unlikely. Those other kids did cared. But they were doing the project as kids do - loosing attention or doing it ineffectively. Forgetting and trying re-over. Having it at bad place and thus having it grow slowly etc. And all that is part of actual doing-projects learning. It is not bad pedagogy to have kids deal with these issues and have them slowly to figure it out. It is bad to then expect the similar result as your daughters had, when the most important decision making was done by you. Or judge those kids as "dont cared".
And this is an actual issue - a kid doing the project the way that is age appropriate and in fact independent ends up labeled as not caring kid. And I think there is value in kids figuring stuff out truly independently.
If you teach your kid the lesson that life sucks and trying is for suckers, don't be surprised when they believe it and don't get anywhere in life because they never try.
If you want to be a cynic don't have freaking kids.
In the working world we call this mentorship. It’s surprising to me that the practice is controversial when applied to children that have so much more to learn.
As such I love DIY science like this.
Regarding crystals, I have scanned in and cleaned up two projects relating to crystals:
http://underlandia.com/index.php/2017/09/24/things-of-scienc...
http://underlandia.com/index.php/2020/08/21/things-of-scienc...
I bet there would be a strong demand for a modern "Things of Science" - youtube is great and all but having a kit put together is a boon for parents
Of course, I'd not want to do her work for her, but more than equally, I'd be quite happy to have a '5% We-encouraging' in her vocabulary when it comes to her explaining herself. What parent wouldn't, if they can?
These can be two different things:
1. Constructive help from parents has (at least) two components. First, it shows your child you care. This may seems small, but it’s not. Second, and I think this is what a lot of HNers would appreciate, is to help your child to develop good processes. There is a lot that goes into this, and it can be parent-centered or child-centered, but having your child reflect on process and (ideally) implement some good processes can really set them up for later in life. Imho, parents should have to write a short narrative about what involvement they had in their child’s project, if any. This is required at some of the local schools where I live.
2. Having the parents do the project for the child is just silly. Most decent teachers can see through this (assuming they care). Congrats to the adult parent for winning elementary school or middle school as an adult. :-/
I entered the science fair as a kindergartner with a poster project explaining how (the output color-mixing of a) color TV worked.
Principal accused my parents of doing it; they had no idea what he was talking about and protested that I’d done it. So he interviewed me about it and left convinced I’d done it. ;)
When in doubt, a simple question like “why did you choose this topic?” or “what was the hardest part of this project?” will usually make clear the driving force behind the project. Some younger kids will just blatantly admit that their parents did the project (sometimes/often to the child’s dismay).
I had an english teacher in college accuse me of cheating. Well accused me in a roundabout way. My paper was on psychosurgery, and violent criminals. He said he needed to ask his girfriend, who had MFCC, how to pronounce amygdala. From then on I dumbed down my papers for him. I would purposely use a bunch of semicolons, and dashes.
I loved to write until I had that guy as a teacher.
I think the big part is to be a mentor. Just asking questions like 'did you think about x', or 'how do you plan to handle y' can have a huge impact by making them think further into the plan without just handing them answers. In my opinion, having them think about the possible outcomes and then search out additional information is really what school is supposed to be about.
My memory of being a kid is that I could not count on my parents to do something I needed. I probably could not have gotten that short narrative from my parents and all it would say if either actually did it was “I didn’t help.”
So, on the one hand, as an honest parent I find such a requirement boundary crossing and a(nother) waste of my time; time I could spend doing something meaningful with my kid. On the other hand, as a former kid, I find the requirement a dealbreaker and I wouldn’t have even tried. Meanwhile, dishonest people are just going to write dishonest narratives.
In practice, what happened was that after we had done our hours, they asked us to do more hours. We said no. Then they cajoled us. We said no. They then essentially harassed us and implied we didn't care about our child if we didn't do more hours. We said no, but this still went on for awhile. You can't escape them either. Even after they stop calling, they gossip about you and get passive aggressive at events. I talked to some parents of older kids and was told that the volunteer organizers only ever bother the parents who actually volunteer. They don't bother with the ones who never do their hours because they figure they never will. So these parents just stopped volunteering altogether. After a couple years of this, I followed their lead.
Second,
The school my child attended was in the same physical building and had the same administration as another school. The two schools used different teaching methods. The population of the school my child attended was about 30% of the population of the larger school. Both schools were neighborhood schools. If you lived in the neighborhood and applied, you got into my kid's school. If you didn't apply, you got into the larger school. If you lived outside the neighborhood you could apply for either school, and IIRC, you got in through a lottery process and only if there was room. In practice, no one ever applied for the larger of the neighborhood schools, only my kid's school. Most people just didn't apply, so my kid's school was smaller and about 30% of those kids were from outside the neighborhood.
Each school had its own PTA. At one point, the larger school's PTA approached our PTA about merging into a single organization. It made a lot of sense on paper, especially since there were "all schools" events. So it happened. The president of the larger school's PTA stayed president. Her first act was to send out a letter to all the parents talking about the merger. It also talked about "putting an end to the special treatment of a select few." In other words, our kids weren't going to get their school-specific field trips that were made possible by our volunteer hours and other fundraisers.
The subsequent meeting was eye-opening. They talked as if the kids' of the smaller school were all little Gates, Zuckerbergs, and Musks, even though most of us lived in the same neighborhood and I only knew of one family with any significant money. Most of these people were wealthier than me just by virtue of owning property in the Bay. We lived in an apartment with rent we could barely afford that was larger than a lot of these people's mortgage payments.
What we thought was going to happen is we were going to merge our PTA's hard-fought opportunities with their sheer number of parents to raise more funds for everyone. What they thought was that we had more money because we were rich and it wasn't fair and they were going to take it and give it to their kids.
Bay Area schooling is yet another thing that makes Bay Area living less tolerable.
As the first in my family to go to college, I was working multiple minimum-wage ($5.85/hr) part-time jobs on top of a full course load just to afford to eat and live. I wrote the professor a letter explaining that this "volunteer" work would be an undue hardship because literally every waking hour that I wasn't in school I was working, so these "volunteer" hours could only come at the expense of work hours and loss of income (which was already not making ends meet).
Her response was that she didn't believe I couldn't spare X hours/week and wouldn't "bend the rules" for me - everyone had to volunteer. The exchange grew increasingly tense until I asked her how much was the activity worth? One letter grade. "Guess I'll be down a letter grade then." (It was a small university and required core course, so I couldn't just drop the class or take with a different professor.)
I have seen this most with larger projects, and usually the student was encouraged to seek outside expertise (just like one would do in real life).
The only catch was that the assistance from the outside sources needed to be documented.
For teens, they can do the documentation themselves. For younger children, a short note from a parent is adequate. If this is a burden to the parent, then I think there are probably some other issues involved.
Like heck I'm gonna sit there writing short narratives for some school. Homework stops at the kids.
What you call constructive help is literally parent organizing and guiding whole thing. If that is what homework project becomes, then it should not be homework at all. It should be in-class experiment, because it so far from being autonomous kids activity.
> Imho, parents should have to write a short narrative about what involvement they had in their child’s project, if any. This is required at some of the local schools where I live.
Personally, I think that homework should be within kids abilities scope - including attention span, access to materials and ability to organize.
I wish my parents had shown interest in stuff like this and supported me to some degree. It’s not about doing the whole project for the kids but showing interest is super helpful. I often gave up on stuff because my dad would basically say “what’s this nonsense for?”
I noticed this when read books about Steve Wozniak and Richard Feynman. Their dads showed interest and encouraged them to explore the world and also challenged them from time to time.
As an example of what I missed out on, while I was on a team of makers I was using a cordless drill and stripped a screw. A coworker poitned out there's a knob that controls the tension of a ratchet, so you can make t he drill stop spinning before stripping the screw. I had no idea, at 45, that was even possible. They had all known about it from early childhood.
It took me many years later to understand that those kids were actually getting help from their parents and I was not that bad actually
But perhaps also a good life lesson because that happens all the time. It’s good to try and develop a healthy self-driven passion. Oh, you don’t care? That’s fine because I do and I learned a lot.
I am picturing you over a mortar and pestle crushing the salt of your enemies whilst a single tear falls into the mix - and en-vigorating (filling with life) - the salt of your defeated enemies..
Perhaps it's you taking this children's assignment too seriously. Was the goal really to find who could grow the best sodium crystal, or was it to teach them how to manage a small project and learn a bit of chemistry? Did your daughter learn anything about those things?
That teacher has a bunch of other kids to educate. Maybe they don't care, or maybe you just have your priorities screwed up a bit.
It doesn't sound as suitable for a take home project
We just accept this as normal. Nothing is less normal than a bunch of children growing up in a building sitting in chairs all day. In an environment that is strictly controlling with harsh limitations on freedom of speech, no tolerance policies for all sorts of relatively innocuous things, and a forced secularism as to ingrain in students the unimportance of spirituality, physical health, personal liberty, and nature. And lets rid ourselves of this notion this is about education, because it isn't. Every step of school is focused on obedience and preparing them for the next step so they will be able to get a job. It is the perfect way to mold a child into an obedient wage slave.
With sensitive compounds, sometimes you can't just let things evaporate. Also as the article states, weather conditions might mess you up. IMO the coolest trick we had to solve this was osmosis of an anti-solvent into a saturated solution.
A small sealed container with a saturated solution of your compound/salt is punctured, and put in a bigger sealed container containing a worse but miscible solvent for the compound under study. Slow diffusion into the inner container causes very reproducible crystal growth, as long as you can control the temperature.
Interested now to try this experiment but with ethanol to better control the crystal formation.
Will be a fun xmas experiment to do!
A) you sometimes spend weeks working on the materials that go into the solution, seeing them feels like a "my god finally" kinda thing
B) under a microscope crystals are especially beautiful, even small crystals. We had a microscope set up in an inert atmosphere for sensitive compounds, see eg.
https://www.jacomex.com/wp-content/uploads/2019/08/microscop...
About timing: this could take anywhere from days to months... really dependent on how fast you can go without making ugly intergrown xtals, on how well you select solvents, etc. Experimental science can be cruel.
Ahh, X-ray crystallography, a.k.a. the field of modern (bio)chemistry that most closely resembles medieval alchemy.
The excellent 2009 documentary "Naturally Obsessed" [0] is about how difficult, time-consuming, and frankly irrational it can be to successfully crystallize certain proteins and protein complexes. The film is about how some PhD students spend the entire five-ish years of their degree programs trying (and mostly failing) to find the secret recipes (protein purity/additive ingredients/temperature/humidity/phase of the moon) that will allow their proteins to crystallize, and thus granting them data with which to populate their dissertations.
Why irrational? In one case, the secret ingredient is pickle juice.
This is amusingly accurate and makes me wonder if our understanding and techniques will ever advance to the point where crystallography no longer feels like medieval alchemy. Surely the process is largely deterministic and we simply can’t control the relevant initial conditions with our current methods.
Check out his copper sulfate crystals if you want something really visually impressive: https://crystalverse.com/best-way-to-grow-copper-sulfate-cry...
I know what I’m doing this weekend with my crystal-obsessed daughter and the bag of copper sulfate I forgot on top of the fridge.
You'll need potassium hydrogen tartrate (cream of tartar), sodium hydrogen carbonate (baking soda), and calcium chloride (sold as DampRid or Pickle Crisp).
Add a spoon full of baking soda and a spoon full of cream of tartar to a glass of distilled water. They should fizz together as the baking soda neutralizes the acidity of the cream of tartar, releasing CO2. This is what you want, since the mixed neutral salt of tartaric acid is more soluble in water. Stir and wait for the fizzing to die down, then gradually stir in small portions of more cream of tartar until the additions stop dissolving. Let the solids settle in the glass.
Meanwhile, dissolve a spoon full of calcium chloride in a second glass of water. It should dissolve readily with a bit of stirring.
Once residual solids have settled in glass one, decant the clear liquid into another glass.
Now pour the clear decanted liquid into the calcium chloride solution with stirring. Within seconds, you should see sparkling needles rain out of the solution. These are your crystals. The transition is especially striking in direct sunlight. The crystals can be saved and seem to remain stable in air regardless of ambient humidity.
I unfortunately have not seen this demonstration written down elsewhere so I can't offer a citation. I came to it by personal experience when I was on a crystal growing kick as a kid. (Though it may well have been written down somewhere that I have never come across.)
[1] Like in this video: https://www.youtube.com/watch?v=AO67MnZaAvQ
That's how my dad and grandfather both contracted a very specific benign bladder cancer. From having their hands in a solvent without gloves. ):
Get a bottle of good red wine, 2010 or thereabouts. Uncork and drink it. Now look at the bottom of the last glass, if you still can, and - voila - potassium bitartrate.
If you don't find any, don't despair and try another bottle.
http://srjcstaff.santarosa.edu/~yataiiya/E45/PROJECTS/Homebr...
The sodium carbonate needed is otherwise known as "washing soda" in addition to being called "soda ash".
I remember this was one of the things I tried countless times as a kid. It never worked - the books showed these nice, clear crystals but all I ever got was a crust of dried salt and maybe one tiny crystal a few mm across.
I'm sure most of those "science for kids" book authors never tried a single one of their experiments.
my grandma saw and told me to use the rest of the string and sugar I had, enough for 12 more tries, and do them at once but in different areas of the house
only two actually grew but i learned the value of spreading risk and unknown unknowns ( much later, on reflection :) )
Made big rocks. https://en.wikipedia.org/wiki/Mother_liquor
A quick check of Amazon.com [1] turned up a bunch of US-looking products, at least.
[1]: https://www.amazon.com/s?k=dishwasher+salt&crid=X6025PAVFBMS...
Plenty of non-american firms sell products in the US. Like... I don't know, Nestlé?
I watched the same Technology Connections video. He does mention Bosch dishwashers by name. Those are available in the US. It's just that people barely bother understanding how dishwashers work, let alone _very infrequently_ refilling the salt. Heck, people drive without checking tire pressures, dishwasher salt has no hope.
Not surprising that most stores don't bother. It lasts forever too.
Most places either have soft water from their water supply, or people install a whole house water softener, if their water is hard enough to cause problems with mineralizing on dishes.
The salt for the whole house water softener would probably work, but the bags are pretty huge.
I am in the Bay Area. I bought some off Amazon no problem. It came from the US too.
> since we we generally don't have dishwashers with built in water softeners that need the salt.
Landlord installed a Bosch dishwasher, which has a water softener. The water is pretty hard (I can see by the shower faucet, and confirmed on the utility website). I'm assuming he didn't bother to import the dishwasher from Europe so it must be available in the US.
I’m not sure about purity or anti-caking, although some brands are advertised as high purity. You can even get it delivered in the US: https://www.amazon.com/s?k=pool+salt
Perhaps look at the 20kg bags of food salt sold at wholesalers, which might not be iodised. I recall seeing one at a Chinese store, but I’m in New Zealand, so I’m unsure about the US.
no.
> I don't think reasonably well-off people in developed countries need iodized salt, because we get enough iodine from our diets.
Depends very much on your diet. Lots of fish, milk, other animal products? Probably fine. Otherwise, maybe not so much.
* Europe is Iodine Deficient (2003) https://www.thelancet.com/journals/lancet/article/PIIS0140-6...
* World map of iodine status (2021) https://www.ign.org/cm_data/IGN_Global_Scorecard_MAP_2021_SA...
* The Krakow Declaration on Iodine (2018) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6140595/
On the other hand, there was one time I had to do a short no-iodine diet and it was pain in the ass. I had had to go out of the way to find non-iodized salt and good luck finding any pre-packaged food without iodized salt...
They should at least recommend distilled water because tap water impurities vary greatly from place to place.
Plain white sugar is also interesting. Alum (used to make pickles, can often be found in the herb and spice aisle at the store) makes neat crystals.
If your kids are old enough to be trusted not to eat the experiments, copper sulfate (used to kill roots that are growing into sewer lines) makes beautiful crystals. It can be found at Home Depot-type stores.
Edit: I see this author has a link to another article on growing copper sulfate crystals down at the bottom of this article. Recommended!
Thank you for the answer, I still remember my alum crystals for the grade school science fair.
Fast-forward many years, and my daughter wasn't having much luck with salt, sugar, or even copper sulfate (that one looked like a melted smurf).
I remembered my alum crystals, which she tried, and lo and behold...nothing! Desperate (on the night before the assignment was due), I remembered someone mentioning that you can make crystals with mothball flakes. We picked a bag of flakes up and heated them up in a dish, and were able to make long, beautiful crystals on the bottom of a cold glass over the heated solution.
The only problem was that as soon as we moved the glass away from the solution, the crystals evaporated, so she took a picture of the crystals as they were forming and received full marks. A happy ending, but the house smelled of mothballs for a few days!
I had a chemistry set as a kid, it had copper sulfate. The only crystals I've managed to grow :)
Some crystals just never form. I know folks who spent 7 years trying to get their protein to crystallize and left grad school with a masters degree instead of a PhD because they failed, no fault of their own.
If the same holds true in 3D, maybe some of these proteins simply do not form crystals.
Sucks to be a PhD student hitting such a protein.
ADP
https://en.wikipedia.org/wiki/Ammonium_dihydrogen_phosphate
and MKP
https://en.wikipedia.org/wiki/Monopotassium_phosphate
and Alum
https://en.wikipedia.org/wiki/Potassium_alum
but probably table salt is cheaper..
I really like Adam's videos, he does a ton of research, and has a very descriptivist approach to cooking in general
The rest is light transport, e.g. lensing via index of refraction: https://courses.lumenlearning.com/boundless-physics/chapter/...
Here's a cool article on a piece of an old spectrometer: https://utsic.utoronto.ca/spectroscopy-beyond-the-visible-sp...
More information from a distributor of optics: https://www.knightoptical.com/stock/default/windows-and-diff...
Guess we gotta grow some!
When visitors remarked on the specimen, my wife often explained that it was a natural salt crystal. Nobody could resist licking it just to be sure.
Still got a beautiful color, but it's got about the same feature definition as a gummy bear...
Anyone got a location on picture 5?
This is a content-less comment but... great article, thank you for submitting.
https://www.appropedia.org/Single_Crystal_Turbine_Blades#Man...
So you probably did get lucky, but depending on the conditions maybe not extremely lucky.
Largest I was able to find was about 2cm to a side, maybe a bit less.. Is there any fundamental reason they don't get bigger than this/lose transparency and form as they grow larger, or is it more that no-one bothered doing growing them larger than that?
TIL it takes a long time to grow a perfect salt crystal of any size.
Well that ends the experiment for me before it even began. AFAIK by law, all salt sold in my country is iodised.
A teacher said, they found it in the woods.