Optic Fiber Model with a Natural Brazilian 
Crystal Tip

This model is the same as the Optic Fiber Unit, but with a natural Brazilian Quartz Crystal inserted at the tip - through which the light passes.  Since Crystals defract the light a bit (depending on the exact angles of the quartz tip) I have used a larger diameter optic fiber to allow more light to enter the crystal. 

Price for the Crystal Tipped Unit