Lithium is a monovalent alkali metal related to sodium and potassium, but is much more deliquescent and is very soluble in water, alcohol, and ether. The second crystal featured in this image, guanidinium chloride, occurs biologically as a neurotoxin and geologically as a mineral that is susceptible to structural changes under pressure. Diet salt (potassium chloride) is thrown into the mix for contrast in this artistic composition. In addition to substituting for table salt (sodium chloride) targeted at sodium-sensitive people suffering from hypertension, diet salt also provides valuable cationic potassium for improving water and electrolytic balance.