A2B(SO4)2.6H2O where A is univalent, K or larger, normally NH4, and B is divalent. B must exist as hexaaquo ion. So, there is in fact no water of crystallization. These compounds are usually highly stable due to crosslinking hydrogen bonds, being resistant to oxidation and erosion in air even if B is Cr, Fe or V. Simply mix the sulfates in solution, and they quickly reacts to form double salt crystals. Even solid sulfates are OK, as a saturated solution of Tutton's salt is not saturated for the simple salts. Monoclinic. If you use no fishing string like me, you may get two different shapes due to different directions(see below), and you can manually turn the diamond one to the brick one by simply turning the seed upside down. It seems that +3 cation strongly impacts transparency. Known examples: Mg: TODO, maybe just similar to the Zn one. V: TODO, purple, extremely reducing in solution. This is far harder than I thought, and crystals shown here are accidentally dissolved. Paraffin ...
评论
发表评论