I wish I'd bookmarked some of the double-salts I'd ran into recently - I assume you don't mind talking about double salts in general because they,
being the broader type of solid which includes alums, sometimes have the same ease of crystal-making. I could've swore I saw a magnesium-something
double salt with chloride or sulfate which made big crystals. It was also a kind of mineral...
Ah, Magnesium Potassium Sulfate (cite). Also, magnesium potassium chloride and zinc ammonium chloride, both with 1:1 of the two cations. I haven't tried any of these, though. And
ferrous and Ferric ammonium sulfates are cool, I own small samples of both. Very pretty. |