Galery 1, ammonium cobalt sulfate
Lab Grown Crystals Picture Galery
© 1998 by Udo J.A. Behner
"Ammonium Cobalt Sulfate"
e.g. ammonium magnesium sulfate doped with cobalt
|| : (NH4)2(Mg, Co)(SO4)2 · 6 H2O
|| : monoclinic prismatic
|| : slowly cooling of the aquaous solution
|| : app. 7 days
|| : up to 5 centimeters
This is a huge specimen of so called ammonium cobalt sulfate but however this is only cobalt doped ammonium
Its an example of the Tuttons Salts which have the general formula X2Y(ZO4)2 · 6 H2O
where X represents either K(Potassium), Rb(Rubidium), Cs(Caesium), Tl(Thallium(I)) or NH4(Ammonium) and
Y can be Mg(Magnesium), Zn(Zink), Mn(Manganese(II)), Cu(Copper(II)), Ni(Nickel(II)), Co(Cobalt(I)), Fe(Iron(II)), Cd(Cadmium), Cr(Chromium(II)!) and V(Vanadium(II)!).
The anion ZO4 may be represented by SO4(Sulfate), SeO4(Selenate) or CrO4(Chromate).
Its supposed that they can form mixed crystals all together so far as they are chemical compatible.
I have also been growing pure ammonium cobalt sulfate which is dark red in color with a little brownish to purple hue, but due to the high
price of cobalt I use this expensive ingridient only as a "dye" to get various color shades of pink and red in
ammonium magnesium sulfate.
This specimen is currently exhibited at the mineral museum in Pforzheim.
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