All the stuff I put online, in one place finally
Formula: NaAl(SO4)2·12H2O
Also known as sodium alum, this double sulfate is among the most elusive alums species. Typycally, alums have comparatively low solubility and crystallize easily, but for sodium aluminium sulfate it is not the case.
Formula: (NH4)2Zn(SO4)2·6H2O
Extremely shiny, extremely transparent: one of the best candidates for crystal growing.
Formula: K2Zn(SO4)2·6H2O
Potassium twin of ammonium zinc sulfate, visually indistinguishable from it. I suspect that precise measurement could reveal some subtle differences in angles between faces, but for the naked eye these compounds look the same. Similarly, baking soda can be used to improve crystal quality (see "Growing" section).
Potassium sulfate K2SO4 is a salt of potassium and sulfuric acid. It is colorless, water-soluble crystalline solid, mainly used as fertilizer.
