© 1998 by Udo J.A. Behner
© 1998 by Udo J.A. Behner
colored with (propably) a mixture of some organic dyes
| chemical formula | : KAl(SO4)2 · 12 H2O |
| crystal class | : cubic disdodekaedric |
| growing method | : slowly cooling of the aquaeous solution |
| growing time | : about 72 hours |
| crystal size | : app. 3 centimeters |
Green was a color hard to get as a water soluble dyestuff.
Also stuff with promising names like malachite green and others
produced only greenish shades of blue or decomposed in the alum
solution. With a commercial mixture to color wood I got this
result.
This specimen is over 20 years old and was one of my early
favourites since the two crystals arranged so nicely on the rock,
just by chance.
This specimen is currently exhibited at the mineral museum in
Pforzheim.