Ionic bonds are formed by complete transfer of electronic from one to another atoms. The compound having ionic bonds generally have high boiling points and melting point because of greater electrostatic interaction. Their electrical conductivity are high and these minerals tend to dissolve in water.
For example an ionic compound sodium chloride has melting point 800°C .
While,
Covalent bonds are formed as a result of sharing of electrons between atoms. These compounds are insoluble , hard, having low melting and boiling points and have low conductivity.
The metallic bond is formed when metals are present. Due to loosely bound electrons of metals, electrons are shared with the other atoms. As this is a weak bond so these materials have low melting and boiling points.
