What are the two main ways in which minerals can form?
- Crystallization through cooling of lava & magma
- Crystallization through solutions
One way that minerals form is when lava or magma cools and hardens to form crystals. (Crystallization is the process of atoms forming a material with a crystal structure.)
An example of this process is the creation of amethyst. When magma cools slowly, deep below the surface, it has time to form large crystals in regular patterns.
The second way that minerals form is through solutions. (A solution is when one substance is dissolved uniformly in a liquid.) When elements and compounds leave the solution, they can crystalize. For example, when magma heats water deep underground, elements and compounds in the surrounding rock will dissolve in the water, forming a solution. If that solution then seeps into cracks in the rock, those elements and compounds will leave the solution when the water cools. The cooling process causes them to crystalize and form minerals inside the rock. These are called veins.
Another method of solution crystallization happens through evaporation. If the liquid in a solution evaporates, crystals will form out of the “left behind” components. For example, when ocean (salt) water evaporates, it leaves behind salt crystals.