As promised, here is the shader arrangement I created for the image above.  Please note the circled attributes, they will change how texture appears at render.  The *Mean_Free_Path_(mm)* attribute on the Custome_Scatter node is the distance, in mm, the raytrace will travel into the surface before it begins to scatter.  You will get a softer surface texture with a higher value (i.e., 14).  The *Ks* attribute on the Ks_microfacet will yield an increased specular highlight with higher values.  You can use this to control hotspots if you use HDRI images in your skydome which tend to be brighter. 

There is a slight transparency applied to this but it is not necessary.  Miss Nancy did point out a thread which I completely forgot about that could improve the shader.  However, I need the time to play with the settings.

The posted render was set up with a skydome (BB's envsphere), one infinite light (approximately 85% intensity).  The reflected light comes from a gradient applied to the dome.  The shader was built in part from a previous thread by Ajax; I stripped out what was unnecessary at the moment.