I prepared these crystals by precipitation, rather than evaporation. A drop of oxalic acid solution on the slide, then a drop of calcium chloride solution at the side of the coverslip. By slow diffusion these crystals appear because of their low solubility.
Better on a slide than in the body: kidney stones
So many other combinations between anions and cations are possible! I tried calcium sulfate (gypsum) from calcium chloride and magnesium sulfate and that worked great, but no pictures.
Calcium carbonate (from CaCl2 + Na2CO3 aq) formed tiny crystals, crystal formation must have been too quick... I know diffusion can be slowed down by a gel - and hey, I found some glycerin-gelatine that I made 40+ years ago that looks and smells as fresh as on day 1 So, that's high on the priority list: use gel to increase crystal size.
Test shots with my new optiphot, improvised with an old enlarger objective as photo eyepiece (50 mm Componon), some PVC and paper cylinders, Olympus E-500, 20x DIC (and POL of course).
calcium oxalate crystals by precipitation
calcium oxalate crystals by precipitation
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- CaOxalaat3.jpg (100.6 KiB) Viewed 1295 times
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- CaOxalaat2.jpg (96.94 KiB) Viewed 1295 times
Re: calcium oxalate crystals by precipitation
Very interesting, thanks
… and very sharp corners ! [ouch]
MichaelG.
… and very sharp corners ! [ouch]
MichaelG.
Too many 'projects'
Re: calcium oxalate crystals by precipitation
Very nice experiment !
Sometimes tiny crystals are formed when the solution contains crystallization nuclei - like dust particles, or when the process is disturbed by a mechanical shock.
But I doubt that any of these happened. Indeed, slow diffusion is the way to go, on a slide.
Sometimes tiny crystals are formed when the solution contains crystallization nuclei - like dust particles, or when the process is disturbed by a mechanical shock.
But I doubt that any of these happened. Indeed, slow diffusion is the way to go, on a slide.
Re: calcium oxalate crystals by precipitation
I should print a T-shirt with 'SLOW DIFFUSION: The Way to go'
You're right about dust, there is some debris visible. I'd better filter the solutions, perhaps with a syringe and cotton pad.
Thanks for the feedback!
You're right about dust, there is some debris visible. I'd better filter the solutions, perhaps with a syringe and cotton pad.
Thanks for the feedback!
Re: calcium oxalate crystals by precipitation
Here's a shot of gypsum, from calcium chloride + magnesium sulfate (any soluble sulfate and calcium salt will work), with my new old Nikon 10x/0.30 e-planachromat.
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