Which statement is not an example of a way a mineral can form?

A.
Scientists grow a diamond under laboratory conditions.

B.
A tourmaline crystal forms from magma cooling very slowly underground.
C.
Pressure underground causes particles in rock to reorganize, forming garnet.

D.
Dissolved substances crystallize on the bottom of a lake as dolomite.
To determine which statement is not an example of a way a mineral can form, we can analyze each option one by one.
A. Scientists grow a diamond under laboratory conditions.
This option describes a process known as synthetic diamond production, where scientists simulate the conditions necessary for diamond formation. This is a valid way for a mineral, in this case, a diamond, to form. Therefore, this statement is an example of how a mineral can form.
B. A tourmaline crystal forms from magma cooling very slowly underground.
This option describes a common process of mineral formation in igneous rocks, where minerals crystallize from slowly cooling magma underground. This is a natural process by which minerals can form. Therefore, this statement is an example of how a mineral can form.
C. Pressure underground causes particles in rock to reorganize, forming garnet.
This option describes a process called metamorphism, where intense pressure and heat cause minerals in existing rocks to recrystallize and form new minerals, such as garnet. This is another valid way minerals can form. Therefore, this statement is also an example of how a mineral can form.
D. Dissolved substances crystallize on the bottom of a lake as dolomite.
This option describes a process known as chemical precipitation, where dissolved substances in a liquid (in this case, a lake) chemically react and form solid minerals, such as dolomite. This is another natural process of mineral formation. Therefore, this statement is also an example of how a mineral can form.
Upon analyzing all the provided options, we can see that each statement is an example of a way a mineral can form. Therefore, there is no statement that is not an example of a way a mineral can form.