What is the difference between diamond and rhinestone

What is rhinestonet?What is the difference between rhinestone jewelry and diamonds?Here is the usually rhinestone type:

1.glass:ground glass rhinestone is very easy to distinguish,because of its low refractive index,not the kind of diamonds flashing
light color,who have a little experience could know  with a glance.This kind of vintage rhinestone jewelry is often used for cheaper
jewelry.

2.synthetic spinel:it lacks the color of diamonds flashing light,put it in to diiodomethane,the outline will be blurred.But the
outline of the diamond is very clear.

3.synthetic sapphire:colorless transparent synthetic sapphire after pondering could as diamond substitutes.But in the diiodomethane it
is almost disappear,while the dark edge of diamonds,very clear.