Question

Is Salt a mineral?

Answer 1

To understand this, we first need to understand what basically a mineral is. And what are the properties that are needed to consider any given entity as mineral? Speaking of its definition, a mineral is an inorganic solid compound that has a fixed chemical composition and stays in a fixed atomic/molecular arrangement.

Complete answer:
Mineral is defined as an inorganic solid compound which has a fixed chemical formula throughout and its molecular arrangement is fixed. For any given compound/ entity to be termed as “mineral”, it must satisfy the following given properties:

1. It must be solid at normal room temperature.
2. It must have a fixed chemical composition.
3. It should have a uniform atomic arrangement throughout.
   If we look at the rock salt, it is a solid inorganic compound at room temperature. It has a melting point at around ${713^ \circ }C$ . Next, we know that rock salt is chemically termed as sodium chloride and it has the molecular formula as $NaCl$ . This shows that rock salt is formed by a combination of $1$ molecule of sodium and $1$ molecule of chloride ion. Hence, every molecule of rock salt will have the same combination of $1$ molecule of sodium and $1$ molecule of chloride ion.
   Next speaking of its structure, we know that $NaCl$ forms FCC lattice in which $N{a^ + }$ is present in the corner of the cube and $C{l^ - }$ is present in the octahedral voids of the cube lattice. Hence it has a similar uniform atomic arrangement throughout.
   Hence we can say that yes, salt is a mineral.

Note:
There are various examples of compounds which may be inorganic solid but may fail the rest of the three conditions. In general, we can say that if there is any compound which is failing to exhibit even one out the three essential conditions to be termed as mineral, then in that case, the compound cannot be termed as mineral.