It is 3.5" x 3" x 1.75" 
Fulgurite...
Using The Power of Lightning For Manifestation
Fulgurite is a form of fused quartz, and is a very special and unique glass, formed by a lightning strike onto sandy soil or sand.
There is an enormous release of energy into the area where the strike occurs, so hot that the sand is instantly melted.
This melted piece forms a glass tube where the lightning passes through the middle of the melted material.
It is this tube that is the basis of what creates the power, that is the basis of why you might choose to use this unusual stone.
Where Is It From? Fulgurite Meaning
The meaning of the name Fulgurite comes from the Latin word 'Fulgur' meaning lightning. Natural pieces of this stone has been found at numerous locations, usually in sandy deserts or at beaches.
They are quite fragile, yet despite this delicacy and fragility they are powerful shamanic tools that anyone can use.
Some particular locations where they have been found are the Sahara Desert, the Gobi Desert and various other deserts scattered throughout the world.
Pieces of this material may be anything from one inch, through to three inches long. They are various colors, as this depends on the color of the sand where the lightning hit and created these tubes.
Why Would You Use It?
These stones embody the powerful energy of lightning within them, that was infused into the stone at the time of the event which caused their creation. This energy makes Fulgurite stones powerful manifestation tools. 
A common use for Fulgarite is for manifesting through the power of prayer. By praying fervently and then blowing your prayer out, through the center of the stone, to the universe, many people believe that this is amazingly effective to manifest.
Fulgurite stone tubes in a range of different colors depending on the color of the sand where the lightning has struck
Its energy forms an energetic bridge between your thoughts and those of the Divine Mind, and it flows in both directions. It is therefore a stone to aid en-light-enment, as through the bolt of light-ning we receive this Divine light.
This is why many people use it on the higher chakras, from the heart chakra up, and including the throat chakra and the third eye chakra.
This stone may be used at any of the chakras, as it well known as a stone to aid you to make contact with the Divine Mind.
At the throat chakra, it will have a healing effect on the ears and the hearing. It may clear the clairaudient channels and accelerate the development of the gift of psychic hearing.
How Will It Help You?
You may understand why the electrical energy of this stone will have a powerful healing ability within the electro-magnetics of the body.
Its intense energy may create cellular rejuvenation, and may prevent cancerous cells from multiplying.
It is also known as a beneficial stone to help those who have electrical sensitivity, as the embodied electricity may assist to normalize electrical activity in the body.
This use was why I increased the number of these stones I have, so that I could utilize them to aid my own electrical sensitivity.
As it may to rouse the kundalini energies, it is also a stone that is known to aid sexuality. The kundalini activation process is best done with the aid of a practitioner, as it has an intense potency. 
If you decide to do this process, you will need eight to ten of the stones. The Fulgurite stones are used in a full body layout, with one at each chakra, one below the feet and if possible two above the head.