Gemstone

Our physical body is made of pancha bhoot (five basic element) : earth, water, fire, air, and ether.
None of these elements have prana (life force).
The electrical body, in and around the physical gives life to it. Example: Imagine a fan without electricity as a physical body. A fan can rotate only when electricity is connected to it. Same happens with our body (like a fan) and electricity (aura).
This electrical body , also known as aura or sukshma sharira , surrounds our physical body and works as a medium to receive energies from the universe and supply positive energies to us. We can also say that this electrical body is nothing but the mirror of our inner body electromagnetic field. That is why, when we meditate and do chakra balancing through mudra and beeja mantra chanting, the dimension and quality of aura changes. Another way to explain is that our body is like a sponge, which is soaked in water i.e auric body. In the absence of this body, we are dead ( as the panch bhoot sharira has no life).