Table sugar is not a mineral because it is in crystal for it is made of more than one element it is not made by a geologic process its chemical composition is always changing

it is not made by a geologic process  

Explanation:

A mineral is any substance or compound which is generated by the geological processes under the surface of earth crust. It is typically inorganic and is not produced by any of the biological process or by the use of any biological agent. They are formed by the solidification and crystallization of magma after the volcanic activities.

The table sugar is not a mineral because it is composed of an ingredient which comes from a biological source that is sugarcane. The formation of sugar crystals from the sugarcane juice is a chemical process. It does not follow geological processes.

when a reversible reaction is occurring in both directions at the same rate; the products and reactants do not change in concentration. a chemical reaction where the compound is broken into its constituent parts.