© 1998 by Udo J.A. Behner
© 1998 by Udo J.A. Behner
doped with traces of nickel
| chemical formula | : (NH4)2(Mg, Ni)(SO4)2 · 6 H2O |
| crystal class | : monoclinic prismatic |
| growing method | : slowly cooling of the aquaeous solution |
| growing time | : app. 5 days |
| crystal size | : up to 4 centimeters |
This is one of the "hand held size" specimen I used
to produce in quantity several years ago.
As the nickel is only contained in traces you get a more blueish
color instead of the expected green.
The nickel is realy sucked out of the solution during the growing
process remaining a practical colorless solution with a very low
nickel concentration. The nickel concentration in the crystal is
several times higher as in the corresponding solution.
Higher concentrations of nickel will result in
"greener" shades with the pure ammonium nickel sulfate
having a slightly blueish dark green color which resembles a lot
to dioptase.
Funny enough as it happens often with dioptase too, if you take a
photograph it will mostly appear to blue on the picture.
This specimen is currently exhibited at the mineral museum in
Pforzheim