Crystal Growing

This will give you lots of very tiny ones. To get a nice big pretty one you should select the biggest of your small ones to use as a seed. Hang this seed into a saturated solution of the CuSO4 by a piece of cotton and it will grow! (you can use a lolly stick to hang the cotton from over the top of a beaker). This may take some practice and some time to get nice big ones...

I too did some crystal growing in my time, by the same method mentioned above. I used potassium sodium tartrate. Attached is a picture of the crystal which I dug up out of the lab.

Crystal growing

Barium chloride

I also tried to grow crystals, took 55 grams of CuSO4 * 5H2O and 100ml of water, heated until all CuSO4 had dissolved and then let it cool.
In the morning I found beautiful CuSO4 * 5H2O crystals on the bottom óf my beaker

I'll include some pictures (sorry for the quality)

EbC: --> Attachment reduced to allow inline viewing...

[Edited on 14-9-2006 by chemoleo]

Vol 2

(How do you add multiple files to one post? :S)

[Edited on 26-3-2006 by Ashendale]

EbC: As above.

[Edited on 14-9-2006 by chemoleo]

Ok, time to show off a little

The crystals below are CuSO4 of course, and I have four of them, weighing 1.3 kg each, roughly 20 cm long. They have been growing for 2 years, with the evaporation method. It was a fair bit of work, because the solution had to be filtered frequently (dust, mold), and topped up, while the growth vessel had to be cleaned out regularly. I grew them in a 10 l bucket (yes with 10 l of CuSO4 solution), because the smaller cups/pots I started off with became progressively too small. Currently they aren't growing, put I might pick it up at a later time. The 2nd/3rd crystal are a bit rough on the right edge, because the last time round it evaporated onto the crystal level, making it all mingy and producing this turquoise amorphous stuff. This is not a problem though, I will scrape it off with a knife, wash it with dH2O a bit, to regrow it in CuSO4 once more. Another problem was the nylon thread I used initially - it was too thin and too weak, so the weight eventually ripped it. The current nylon thread takes 9kg, so I still have some leeway. But if you plan big crystals, use the stronger thread from the start, because fixing it later onto a grown smooth crystal (such as the first one) is very difficult, in fact I had to saw into edges a little to fixate the thread. Again, no problem if it is cleaned nicely after that, and regrown. Sadly the quality of the crystal suffered a little from it. However, if you grow it long enough, the crystal layers become so dense you can't ever see the fault.
Other than that, they are the proudest pieces of my collection!

Mephisto upped those pictures on LambdaSyn, with more details given there (German).

1.3 kg! Each!!!!

Those are pretty impressive chemoleo, though I don't think I have any plans for getting a 10 L bucket to grow crystals in just yet

Well thank you. Very interesting what you mention on quartz crystals, I have one sitting right on top of my computer screen, and I always wondered under what conditions it might have formed. I alwyas thought it was formed by melting and cooling, but never could explain why it would, for instance, sit in those globular rock balls - which are cut apart and contain lots of quartz crystals. Now I know - who would have thought SiO2 is soluble in water at 300 deg C ? I gotta get one heavy duty autoclave! Do you have more information on SiO2 crystals, i.e. how they are made commerically?

As to the KH2PO4 crystals - I actually saved an article on this from the BBC website, published 15th Feb 2000:

Quote:

Lab grows monster crystal It measures 66 (cm) by 53 by 58. If you ever struggled to grow copper sulphate crystals in a jam jar at school, look enviously at this monster. The pyramid-shaped KDP (potassium dihydrogen phosphate) crystal is a record breaker. It weighs in at an astonishing 318 kilograms (701 lbs) - more than 20 kilos heavier than the previous record holder. It was grown in just 52 days by researchers at the US Department of Energy's Lawrence Livermore National Laboratory, California. The enormous crystal is to be sliced into plates for use in a giant laser now under construction at Lawrence Livermore. The crystal plates will convert the laser's infrared light beams to ultraviolet light just before the beams strike the laser target. The new equipment will test the safety and reliability of America's nuclear weapons stockpile. The growth technique builds on Russian methods. Russian technique To grow crystals this big, Lawrence Livermore built on a rapid-growth technique first developed in Russia. A thumbnail-sized seed crystal is placed inside a two-metre-high tank filled with nearly a tonne of supersaturated KDP solution at 65 degrees Celsius (150 degrees Fahrenheit). The temperature is gradually decreased to maintain supersaturation as the growing crystal extracts salt from the solution. The record size of the latest crystal was achieved by giving the solution a transfusion of additional salt through a device called a continuous filtration system, which helps maintain crystal quality. "This technique offers the possibility of producing even larger and higher quality crystals in the future," said Ruth Hawley-Fedder, group leader for the Livermore crystal growing team. "Our newest record holder could have grown even larger, but we simply ran out of room in our growth tank." Images by Jackie McBride and Bryan Quintard, Lawrence Livermore National Laboratory

Very Very nice chemoleo, thank you for the inspiration, I will most definately be attempting this project myself,

Here is a nice description of the hydrothermal growth process for quartz crystals.
http://www.roditi.com/SingleCrystal/Quartz/Hydrothermal_Grow...

Note how the "Low Pressure Process" uses "only" 700- 1000 bar.


My attempt at growing large sulfur crystals failed.
At first, only monoclinic crystals were formed, very long and very thin needles.
I read up and it found that at temperatures of about 95°C, only the monoclinic form of sulfur is stable.
So I added more toluene (a total of 65ml for 6g sulfur) to lower the temperature at which sulfur begins to crystallise, and also 1ml of CS2 (I know that slow evaporation of a CS2 solution of sulfur makes rhombic crystals, so I thought that a small amount of CS2 could favor rhombic shape).
I used a water bath to heat the hermetically sealed vessel, and let it cool down in the covered water bath (the water bath serves as thermal ballast to slow down the cooling).

It actually makes rhombic crystals now, but they are small and there are a lot of them. They also have this very strange behavior to grow into needles with the rhombic crystals on them like a string of pearls.
The individual crystals are very good though, a pure yellow and absolutely clear. They also redissolve very slowly, even when the toluene is hot enough to allow complete dissolution.

The crystalline sulfur would look great as an element sample, much nicer than the powder one always sees.

chemoleo's crystals are quite impressive. At first, I didnt notice the coin, once I did, WOW.

Copper (II) Chloride works pretty well for growing crystals too.
I made some CuCl2 once and left it in a pan to dry. I forgot about it for a month and when I came back, it had formed into green and blue (Hydrated I assume) crystals on the sides and bottom of the container.
Had I been trying to make crystals and put a seed in there to start, I probably could have gotton something pretty good.

CuCl2 sucks for crystallization, it makes those acicular mats of crystals :rolleyes:

[How come we *still* don't have a rolleyes smiley?]

That's an interesting bed of crystals though

I've got a salt that makes large crystals easily, I have no idea what it is, it seperated from my failed urea fermentation experiement. When I grow a big crystal I'll take a picture...

Tim

No, CuCl2 actually dissolves better in very concentrated HCl than it water. This is due to complex formation. A yellow/brown complex is formed, most likely CuCl4(2-), but probably also HCuCl4(-) and H2CuCl4. The crystals, obtained by crystallization from HCl contain a lot of acid, and they also have a different color than pure CuCl2.2H2O. The pure salt is cyan/blue, the stuff, obtained from HCl to my experience is much more green with a yellow tinge. Below follows a picture of CuCl2.2H2O.



[Edited on 7-9-06 by woelen]

Ya, about the same as my stuff (see my copper salts page).

The stuff I get is certainly green when moist, but I always attributed that to solution, which is certainly going to stick well (capillary action) given the nature of the hairy crystal blooms.

Well I crystallized some more just today, check it out for yourself.





(Second is sideways and upside-down view of same.)

Most of the liquor has been poured off, which means there's plenty still stuck inside the growth, which has to be broken up and squeezed in filter paper (vacuum would be better!). The liquor is definetly thick deep green, with only a tinge of yellowness. It looks yellower on soaked paper towel, but I would like to think that's due to stuff in the paper oxidizing (copper shouldn't affect cellulose much in that way, though).

Your product may be a bit bluer than mine, lemme see... eh the contents of this jar (now much more than just the little bottle shown on my site) is definetly not as dramatically blue as yours. On opening it smells strongly acidic, not of any particular odor (except the odor that wasn't well cleaned from the jar before I got it). Maybe I'll dry it out a bit more...

Tim

[Edited on 9-7-2006 by 12AX7]

Giant gypsum crystals the size of trees!

Now I just wish I had some of these! Look at the size of the person!




They just recently worked out how such big crystals could form naturally. Check http://www.spiegel.de/wissenschaft/natur/0,1518,476553,00.ht... for the Germans here.

In a nutshell, this is 300 m below ground, found through mining, in a grotto in Mexico, the Chihuahua desert (Naica).
Up to millions of years, 54 deg hot water filled this grotto, depositing CaSO4*2H2O, and the temp must have been extremely stable otherwise the crystals couldnt have grown (i.e. the anhydride ones would have formed instead). The crystals are now in the dry becuase groundwater is pumped away for mining. As soon as the pumps stop, the crystals will start growing again!
For reference, the biggest such crystal made in a lab measures 2 cm in length! If one of these crystals is 10 m long, and say that it takes 1 cm/year for growth (which is likely an overestimate), then they would have been growing at least 10000 years!

Darn I'd love to have one of these in my house!

The original article from the journal 'Geology' is here
http://www.gsajournals.org/perlserv/?request=get-abstract&am...

Those are amazing! I bet its closed and no tours though. I would love to see them in person.

I can't imagine they wouldent use as much fancy lighting as possible for something like that!

naah, these are more a Mega deep Emerald green towards Black.
powdered or scratched they`re Emerald green, whole they`re Black to look at.
and potassium Permanganate when In large crystals would be a good analogy, they too can look almost black when perfect

Crystal Growing

At work I accidently grew a crystal 1cm x 1cm x 5mm of bromoadamantane. Thats what I get for leaving my waste in a beaker evaporating because I was too lazy to empty the full organic waste bucket.

I will post a pic tomorrow, it adopts a form similar to how bismuth crystallizes, but colorless.

Favorite Crystal Growing Chemicals

Earlier in this thread YT2095 shows nice pictures of copper acetate he made. I presume this is cupric acetate.

I am attempting to make same, but I think my synthesis is going bad and I'm getting Cu(OH)2 instead. Here's what I did:

I reacted stoichiometric amounts of of Ca(OH)2 and white vinegar (5% HOAc) to form Ca(OAc)2 in lots of water. Then I added a stoichiometric amount of CuSO4*5H2O.

Ca(OAc)2 + CuSO4*5H2O --> Cu(OAc)2 + CaSO4*2H20 +3H2O

The gypsum was then removed by filtration, which is not hard when using a little diatomaceous earth added and a Buchner funnel.

Then I placed this navy blue translucent solution, which I assume to be aqueous Cu(OAc)2, on a hotplate-stirrer to evaporate off the water. But, it turned into a light blue slurry upon heating and vapors smell strongly of acetic acid. Hence my assumption that I'm forming a Cu(OH)2 slurry out of my dilute Cu(OAc)2. Right?

Now my question for YT2095: How please did you make your nice dark green crystals?

And, if anyone else can offer a method for making the Cu(OAc)2 please do. I searched but could not find one.

Because I am a skinflint.

And thanks Un. Chaos for the insight on the CaSO4 formation. I guess that batch is toast.

Maybe not toast. I turned off heat, let it cool, then turned off stirrer. White solids (CaSO4) quickly settled out leaving a dark blue translucent supernate with no apparent Cu(OH)2 ppt gel. pH is slightly acid. So maybe some Cu(OAc)2 is recoverable here. I will filter again and go from there.

[Edited on 16-4-2008 by Magpie]

[Edited on 16-4-2008 by Magpie]

[Edited on 16-4-2008 by Magpie]

Just now I wanted to write, triethylamine HCl doesn't crystallise well (as I've found that it forms needles which are very hygroscopic) and dang, there it is, you are writing on triETHANOLamine HCl
Where did you get the triethanolamine from?

On the matter of CuAc2 - I've made liters of the stuff using this very method, with CaSO4 - CaCO3 was dissolved in 25% HAc until it would dissolve no more, and to this the calculated amount of CuSO4 was added. This was filtered, rinsed more with cold H2O until the CaSO4 on the filter went pale green blue. The supersaturated solution started crystallising finest CuAc2 in no time, as glittering dark green crystals, which were so small that it was essentially a powder that could be filtered off and dried. It keeps well for several years. The CuAc2 at the time was used to produce lead acetate with Pb metal.
Anyway, I'd perhaps omit the boiling step, and work right away with highly concentrated solution. THat should allow you to filter off a significant amount of beautiful pure CuAc2.

Potassium triethanedioxatoferrate (III) crystals are bright green, and looked spectacular. I can remember making some at school when we were learning about transition metals, shame I didnt take any pictures Anyway heres the equation if anyone wants it:

FeCl3 + 3K2(C2O4) => K3[Fe(C2O4)3] + 3KCl

Basically we made weighed out stoichiometric amounts of the Iron (III) chloride and the Potassium oxalate. The FeCl3 was dissolved in half of the amount of water as the Potassium oxalate, and the two resulting solutions were mixed in a small beaker and covered. Unfortunately I have a feeling that the compound may be light sensitive, as the textbook has made the note "leave a sample exposed to sunlight or powerful light".

Quote:

Originally posted by Magpie Now my question for YT2095: How please did you make your nice dark green crystals?

Thanks YT2095 for the method on your large crystals.

Mine have been growing for about 2 days now. I have two shallow dishes sitting in a window (eastern exposure) to warm in the morning sun as shown.

I took a picture of it, for a while I did consider it being a Cu(I) salt but I have no way of confirming it. One thing I did notice though, the solution smells strongly of acetic acid and I can't see why it should.


Any ideas?

that Almost looks like the copper carbonate I start with

I see, thanks. I did imagine the acetate was deprotonating the water and thus forming the hydroxide, the problem was I couldn't picture where the hydroxide would go so I didn't know exactly how to explain the vinegar smell. Now that you mention the possibility of a basic acetate it makes sense.
Anyhow, is this stuff good for anything useful/interesting?

For the record, here's a picture of triethylamine hydrochloride...not a good target for growing nice crystals

[Edited on 13-5-2008 by chemoleo]

Ah, indeed! Only, those are fucking impossible to scrape off the sides! ARGH!

Tim

I have been seeing what copper(II) compounds I can make with root killer CuSO4*5H2O. I have made Cu(OH)2, CuO, Cu(OH)2*CuCO3, and Cu(OAc)2*H2O.

The Cu(OAc)2*H2O was made from my homemade cupric hydroxide using 10% acetic acid made up from GAA. Below is a picture of a few crystals, which have a very dark color and smooth faces. They are prismatic and 3-4 mm wide. The end of the pestle shows the color of the crystals when ground. In the bottle is the basic cupric carbonate.

What has got me puzzled is the blue color of the carbonate and the acetate. I was expecting green for both. Brauer calls the carbonate "green copper carbonate", or "malachite." YT2095's acetate crystals were dark green in accordance with my CRC handbook.

(However, I have an abstract of a 1940's Russian journal article that says the acetate crystals will be dark blue.)

So, does anyone have an explanation for these apparent color discrepancies? What have been your experiences?



[Edited on 3-6-2008 by Magpie]

certainly, here you go:



the far left is the crystaline copper acetate, in the middle is the same but ground up, and the far right is my copper carbonate as Azurite.
with the carbonate, if I`m going to have the lid off for any length of time, I fill the jar with CO2 when I`m finished and put it back on the shelf, it keeps nicely that way.

copper sulphate and washing soda will work just as well as my method, the only reason I do it the way I do is because nitric will dissolve copper metal in minutes without any fuss (and I have plenty of it), and I use K2CO2 because if I used the carbonate in any pyro mixture I wouldn`t want Any sodium ions to contaminate the color.
you still have to wash it very well after making it though.

as for the acetate you`l probably have to make a larger and more concentrated amount, and rather than crystalise this in a shallow dish try something a little taller and evaporate more slowly, it should give you larger crystals.

here`s another nice copper salt, perfectly clear blue, but lighter than copper sulphate.

it`s Copper Malate, simply made buy adding copper carbonate to malic acid soln and crystalising, it`s a little more difficult than some salts as it tends to get very viscous as it evaporates and can form a skin on the top, a bit like making sugar crystals.
the color is quite nice though.

Here's a picture of the big crystal of cupric acetate monohydrate grown from a seed crystal. Next to it are the normal sized crystals that started on their own.

These were grown from unfired CuO rather than fired CuO as I reported earlier. I couldn't get the fired CuO to dissolve.

Also shown is the blue homemade basic cupric carbonate compared to the green pottery grade of basic cupric carbonate. This color difference really puzzles me.

I couldn't say it better myself. When I look at my crystals in the picture above I can almost say I see a very dark green hint. But when looking at a thin edge in good light I see a gleam of blue.

Bereal I also thought that the green material just had less CuCO3 vs the blue. This is the conclusion I got when comparing the procedures in Brauer.

But when I fired samples of the two grades, then reweighed, my results supported an opposite conclusion. The ratio of CuCO3/Cu(OH)2 in my blue product is 1.08, in the green pottery product it is 1.24!

The first method in Brauer, p. 1024, (Green Cupric Carbonate), in the forum library, is what I used to make my blue carbonate. Starting material was CuSO4*5H2O.

Now the experience of UnintentionalChaos with CO2 applied to wet blue carbonate also supports the conclusion that the more carbonate the more green. Again, this is opposite to Brauer.

When you see the green patina of copper exposed to the elements as in a copper roof or work of art it is usually green. This would also indicate an exposure to CO2. An example can be seen in the picture below which is of a piece of copper sheet metal on a very old wind chime in my backyard.

[Edited on 8-6-2008 by Magpie]

The propionate now is drying, it looks quite a lot like the acetate.

I now prepared the following salts (fine crystal mass):

1) copper acetate
2) copper monochloroacetate
3) copper trichloroacetate
4) copper propionate

I did a nice observation. In solution, only copper acetate and copper propionate seem to be heavily coordinated. The solution is darker than e.g. a copper sulfate solution of similar copper concentration, and the color is more greenish.

Copper monochloroacetate is not greenish at all in solution, it is more like a concentrated solution of copper sulfate. The picture below shows a solution of copper acetate and copper monoacetate.



A solution of copper trichloroacetate looks the same as a solution of copper monochloroacetate, plain blue copper ions


When the solid is made, then, however, the monochloroacetate becomes a coordination complex, the solid looks more like plain copper acetate. The trichloroacetate, also in solid form is not like the plain acetate anymore. It is bright blue like copper sulfate or copper nitrate. The picture below shows from left to right the plain acetate, the monochloroacetate and the trichloroacetate.



So, it seems as if the chlorine on the acetate ion makes coordination with the copper ion weaker (more labile). The monochloroacetate still is coordinated in the solid, but in solution the complex dissociates and a plain blue aqua complex is formed. The trichloroacetate is not coordinated at all, the solid also seems to contain a simple hydrated copper ion.

All three copper acetates are non-hygroscopic. They can easily be dried and form a nice dry non-sticky powder.


The solution of the propionate resembles a solution of a plain acetate.





When I have the dry solid copper propionate, then I'll make a nice write-up in a web page, but here you already have a few pics.

[Edited on 12-6-08 by woelen]

<!-- bfesser_edit_tag -->[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: fixed broken image(s)]

[Edited on 7.1.14 by bfesser]

Vera nice. What were your starting materials? What color are they? I.e., more blue than green, more green than blue, or blue-green, etc. (I'm thinking the camera may distort this color somewhat.)

wow, those are Beautiful specimens, Well Done!

whilst on the subject of crystals, has anyone ever seen crystals growing on Top of the liquid layer?
I have some sodium oxalate that I`v made for use later, and am now letting it crystalise.
it has formed a "raft" like island on the top of the liquid layer and on this "Island" crystals are growing Upwards on it like little mountains.
I`v seen a skin form of certain solns before, but I`v never seen this happen.


[Edited on 10-7-2008 by YT2095]