I had someone "help" me to save $ & laid the 12x12 granite tiles on my existing counter... he did nOt smooth the edges! What can be done at this point... its "glued down" & he trying to figure out what to do now on edges!! Help!

When installed did you put factory edge to the front?

You can use 1/2'' oak by 1 1/2'' as a facing. This can be nailed to existing counter edge.

Chuck

Home Depot sells 12 x 12 x 3/8 granite tiles with no finished edge.
It's a little late to add a smooth edge. I'd put a wood edge under it as Chuck suggested. It's not a bad 'natural' look.
HD sells some very pretty wood trim with a leaf pattern pressed into it, in various widths and lengths.