During crystallization, are crystals formed by various solutions always pure and edible ?

Solution:
The principle of crystallization is based on the limited solubility of a compound in a solvent at a certain temperature. Generally, during this process, the compound is soluble in solvent whereas the impurities are insoluble. The solution is filtered and cooled. 
The crystals of the substance are formed.
Yes, it is pure but whether it is edible or not depends on the compound which is crystallized. Every pure substance is not edible.