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Endo
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@ Peach
Thanks a ton for the ideas, after talking it over with her and indicating how little time we have left she decided that she likes the anhydrous vs
hydrated salts demonstration. We will go this route as it is much easier with the time we have left. Thanks
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peach
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Erm... yeah... there is a price on that information.
I want to see the project.  
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Arthur Dent
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Deleted text because of replied post removed... 
Robert
[Edited on 3-3-2011 by Arthur Dent]
--- Art is making something out of nothing and selling it. - Frank Zappa ---
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Elawr
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I've enjoyed some success at growing FeS04*5H20 by keeping my supersaturated solution acidified by adding a little H2S04, sealing the container, and
keeping few common iron nails (NOT galvanized) in the liquor while crystals grow. The solution will remain clear, and nice green crystals will emerge.
I suspect it is the Fe(III) state that muddies things up, and that the presence of elemental iron and excess (SO4)= in the solution strongly favors
Fe(II) instead.
[Edited on 3-3-2011 by Elawr]
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Morgan
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Tidbit on potassium dihydrogen phosphate
National Ignition Facility shorts
http://www.youtube.com/watch?v=hMRD2Ckmmes
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hissingnoise
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I once read an article somewhere where German researchers grew very large crystals of HMTD.
They found that, at a certain particular size, the crystals detonated entirely spontaneously, due presumably, to lattice-strain!
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Morgan
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A long time ago I remember reading a book on growing crystals and one I thought interesting was growing Rochelle salt I think. After you had your
large crystal it said to take a bit of vaseline to cause two aluminum foil strips to stick to the sides of the crystal. Wires were connected to the
foil. Then a thin piece of cardboard was placed on top of the crystal. You then got your friend to hold the wires while you strike/rap the crystal
with a hammer, shocking your friend, all in the name of science of course. ha
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aonomus
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Quote: Originally posted by hissingnoise  | I once read an article somewhere where German researchers grew very large crystals of HMTD.
They found that, at a certain particular size, the crystals detonated entirely spontaneously, due presumably, to lattice-strain!
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I wonder how many crystal growing apparatus setups they destroyed. It always seems to be the Germans in Angewandte Chemie that are making molecules
with more nitrogen than carbon....
As for the rochelle salt, I think the fact that it is an easily accessible piezoelectric crystal is great.
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slinky
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Bismuth crystals look amazing. They look almost alien, something hr gieger would appreciate. Here's some how to guides.
http://www.amazingrust.com/experiments/how_to/Bismuth_Crysta...
http://www.autarchex.com/projects/growing_bismuth_crystals
<img src="http://www.sciencemadness.org/scipics/Bismuth.jpg" width="800" />
<!-- bfesser_edit_tag -->[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: reduced
image size(s)]
[Edited on 10.12.13 by bfesser]
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Poppy
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| Quote: Originally posted by Sedit | | Quote: Originally posted by chemoleo | | Same here - I was hugely disappointed with ferrous ammonium sulfate - not only is the colour ugly, but also it's prone to oxidation. But I didn't have
much good experience with FeSO4 hydrate either... the iron curse! |
I know this is a rather old post but how did you attept to make the FeSO4 crystals chemoleo? I boil iron(steel?) in H2SO4 before which left me with a
grey material IIRC which turned green with the addition of H2O. The green solution was filtered and left overnight in a jar where Large FeSO4 crystals
grew all over the bottom with some rather large almost 1 ince in size. If left out oxidation is a huge problem and the "crystals" turn earth tone red.
The solution also began to form brown precipitate until the Green color was completely gone. I think the trick is to start with as concentrated
solution as possible and cap it ASAP and allow it to grow or else it will just form brown shit. |
Surely when making ferrous sulfate out of cast iron you got to filter the carbon content of the iron first, thus leaving a cyan-green solution, which
must be kept acidic and away from daylight to prevent iron II from oxydizing into iron III which is brown and much more insoluble. I have a guess
those hexa or heptahydrate salts must be much more difficult to grow than conventional crystal lattices that excludes water from them. They're
beautiful but troublesome
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GreenD
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you guys ever see this cave in russia?
http://www.stormchaser.ca/caves/naica/Naica_08.jpg
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quicksilver
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Pushing 2cm of TNT crystal growth:
http://www.sciencemadness.org/talk/viewthread.php?tid=29&...
Unfortunately there is nothing to compare a table of length but the beaker on the rt (TNT) had some amazingly long needles.
EDIT:
Do you have any more information on that Russian cave? That's incredible!
[Edited on 8-2-2012 by quicksilver]
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Poppy
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They pushed that too far.. too far... Crystals won't fit the cave exit anymore. Hopefully may us all grow crystals like these someday?
Now seriously guys, I've been so "seriously" trying to grow ammonium dihydrogen phosphate crystals with just a beaker and a bain marie pan at best.
The result is that the crystals grow but the tiny parasitic crystals growing on them seem to disturb the whole process because they excuselessly off
spring in the beaker walls so the shot there might work is that the iny crystals grow over the seeds and get recombined by ion exchange forces. This
realy happens when powder turns into crystals when wet and at rest. If this don not proceed the seed must be suspended with latex fishing string, or
just any very fine nylon string, in the solution and then create a miniramp where the recently formed zit crystals may slide off to the bottom leaving
this suspended seed at least untouchable, if not at a good growing rate.
I shall give results soon enough.
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turd
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Mexico! It was all over the news a few years ago:
https://en.wikipedia.org/wiki/Cave_of_the_Crystals
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Magpie
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Those crystals look amazingly like the CaSO4*2H20 crystals found in a cave in Mexico. See the post by chemoleo, this thread.
http://www.sciencemadness.org/talk/viewthread.php?tid=5529&a...
The single most important condition for a successful synthesis is good mixing - Nicodem
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plante1999
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I would like to know if anyone know how to grow malachite, such as the one in this paper.
Thanks!
Attachment: Man-Made-Jewelry-Malachite.pdf (392kB)
This file has been downloaded 1165 times
I never asked for this.
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Morgan
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If this hasn't been posted, there are lots of pretty quartz crystals and some history and science behind them.
Russian Synthetic Quartz
http://www.youtube.com/watch?v=PKQOSPwodWY
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cpman
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Currently, I'm growing single crystals of monoammonium phosphate (NH4H2PO4), copper II acetate
[Cu(CH3COO)2], and potassium alum. Also, I'm dissolving some zinc in vinegar to make zinc acetate for crystal growing.
The monoammonium phosphate is really annoying, as every single crystal I try to grow turns cloudy because the temperature of my house is not super
stable, and I tend to make the solutions when the house is at its warmest. The others are fairly easy.
[Edited on 12-10-2013 by cpman]
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blogfast25
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NH4H2PO4
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Zephyr
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Some almost finished stannous chloride crystals.
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Oggas
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Crystallization chamber
| Quote: Originally posted by aonomus | Thats interesting that 5-10% NaOH causes the NaCl to saturate. I'll have to try that this week.
I'm also in the process of building a crystallization chamber based on the rotating platform setup the LNL used to grow massive KDP crystals for their
big lasers.
http://education.llnl.gov/crystals/Sketch.html
[Edited on 25-7-2010 by aonomus] |
Anonomus I was wondering how the building of the crystallization chamber was going? It seems I can't view the reference you are quoting so I'd love
any info on how you did it. Been having trouble finding good references on how to build one.
Anyone else got any ideas?
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Sniffity
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I also tend to use the seed crystal on a string method for growing large crystals. I get annoyed to no end by the string being unremovable after this
D:
I've tried planting a single seed crystal on the floor of the beaker, but invariably more crystals will form (I'm guessing due to seeding by
impurities) which will eventually trap my big crystal on the bottom.
Any ideas on getting a large crystal without the use of a string?
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Bezaleel
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The only - really sophisticated - method I can think of (only works for diamagnetic crystals) is by suspending the crystal in a magnetic field. This
requires extremely strong magnetic fields.
Practically we're limited to less sophisticated methods. I've always grown my crystals on monofilament threads. Seed crystals I took form the bottom
of my beakers/flasks.
The only practical general method (I know of) for "suspending" a crystal without the use of wires is by an upward flow of the mother liquor. Requires
cunning tuning of the liquid flow.... And I imagine is to be very difficult to prevent the saturated solution from forming crystals inside your pump.
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soniccd123
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| Quote: Originally posted by Sniffity | I also tend to use the seed crystal on a string method for growing large crystals. I get annoyed to no end by the string being unremovable after this
D:
I've tried planting a single seed crystal on the floor of the beaker, but invariably more crystals will form (I'm guessing due to seeding by
impurities) which will eventually trap my big crystal on the bottom.
Any ideas on getting a large crystal without the use of a string? |
I got a pretty big Copper Sulfate crystal once using a seed on the floor of the vessel, with time, more crystals really formed, but every time this
happened, i just took the crystal i was growing out and filtered the solution.I kept doing this till i was happy with the size of the crystal.
I tried this with Iron(II) Sulfate and Cobalt(II) Sulfate and the first one worked like charm but with Cobalt, on the other hand, i could grow the
crystal only till it got like 5mm, then it started to get quite hazy (in fact, i still don't know how to grow a big Cobalt Sulfate crystal, they all
get very hazy and strange when bigger than 5mm more or less).
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knowledgevschaos
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I've had a few ideas, and I just thought I'd dump them here.
A few people seem to have trouble with a crust of crystals creeping up the edges of the container. I've had this problem too, particularly with copper
sulfate. My theory is that this happens because the meniscus on the glass draws the solution up into a thin layer that evaporates more rapidly. I
think that by rubbing the glass with an oil / petroleum jelly, the container would repel water, and this wouldn't be a problem. I haven't been able to
test this yet though.
Solutions going moldy also seems to be a problem for many compounds, especially sugar and rochelle salt, and I think it could happen to ammonium
dihydrogen phosphate too. I've even had magnesium sulfate grow microbes (how an organism can thrive in a saturated MgSO4 solution is beyond me!). Some
people have suggested using iodine to kill microbes. would tincture of iodine (2.5% I2, 2.5%KI) be enough to kill the microbes, and would the
potassium iodide interfere with the crystal structure?
Thanks everyone.
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