It is possible to form "Halo"

Well think about light in real life. Let's say you have a ball and a cube and they let light go thru them. Regardless of whether you put the light into the cube or in the ball, the light's halo will look the same.

However you might be looking for a specific effect, in which case you might need specific glowing shaders. I recommend for starters using the Standard shader and setting the emission color and intensity. This is the doc for that: http://docs.unity3d.com/Manual/StandardShaderMaterialParameterEmission.html

Actually I set up a test scene to show this. Also you should add a Point Light to your cube so it will actually emit light. Take a look at this picture:

You can see that I have a cube with a child. The child is the point light, which makes the cube glow in a totally dark enclosed square room..

I hope this demonstration helped your understanding of shaders and lighting!