Grindelwald taught Tom about making Horcruxes

[Hagrid]

No: HPFGUIDX 139599

Tom Riddle made the diary Horcrux in about 1942 or 1943 ... is that 
correct? So where did that 16 year old learn how to make Horcruxes? He 
didn't learn that in Hogwarts.

I propose Grindelwald taught Tom about Horcruxes. If that is so, 
wouldn't Grindelwald also have made a Horcrux or two? He could teach 
what he knew.

Now, JKR has said Grindelwald was defeated, but in her latest 
interview, there was a lot of unanswered questions about that Dark 
Wizard. 

I have some more ideas about him ... without making this TOO long, let 
the discussion begin and see if we have similar theories.
-aussie-