Final answer:
In evaporated seawater, the most abundant mineral to crystallize is sodium chloride, or salt, due to the high concentrations of sodium and chloride ions in the seawater. The sequence of crystallization may include other minerals like magnesium and calcium salts as water further evaporates.
Step-by-step explanation:
When seawater is evaporated, the mineral you would expect to find the most of is sodium chloride (NaCl), commonly known as salt. Seawater is a solution containing a variety of salts, with sodium and chloride ions being the most abundant. Salt ponds, like the ones located near San Francisco, are examples of where seawater evaporates, and sodium chloride begins to crystallize out, a process facilitated by the high salinity that can reach levels ten times that of seawater. In contrast, the Dead Sea is a unique and particularly hostile environment, where seawater is even more concentrated, having high levels of other minerals like magnesium (Mg), calcium (Ca), and iron (Fe), which contribute to the water's 'hardness'. However, in the open ocean, once seawater evaporates enough for sodium chloride to precipitate, other minerals that may crystallize include magnesium salts and calcium salts, depending on the saturation levels and the presence of other ions that affect the order of precipitation.