Pardo Translucent Art Clay from Viva Décor is one of the clearest translucent clays available! 

Pardo Translucent and Pardo Translucent Agate give you more options - read more about it in this article from The Blue Bottle Tree - Pardo Polymer Clay – A Tale of Two Pardos

Note - Pardo Art Clay Translucent and Pardo Translucent Polymer clay are the same item. Various places on the Viva Décor web site refer to it differently.