There are three types of rhinestone, flat back rhinestones, hotfix rhinestones and sew-on rhinestones.

1. Rhinestones types
There are three types of rhinestone, flat back rhinestones, hotfix rhinestones and sew-on
rhinestones.
Flat Back Rhinestones: These are available as foiled or un-foiled, the un-foiled are often used for
setting into jewelry pieces where it’s desirable for the light to be able to pass through the crystal.
The foil backed crystals are the most popular kind and can be applied to just about anything with
a little adhesive and some imagination.
Hotfix Rhinestones: Are just like the foil backed rhinestones with a ready applied adhesive
backing, they can be applied with heat either from a hotfix applicator or an iron with the steam
turned off.
Sew on Rhinestones: As the name suggests sew on rhinestones are just stitched into the design
or in the case of jewelry making they can be linked together with jump rings or wire. They look
much the same as flat back rhinestones but with a hole each side of the crystal.
Source from：http://www.webeads.com/types-of-rhinestone/