Paul,
There are a few products on the market that would probably work. Contact Cement from Dupont would work. Devcon also has a very good adhesive as does Quick Grip from a company called Beacon. Make sure the adhesive is clear or dries clear, you wouldn't want a white glue line running through the middle of your chip. Use a small amount as too much might cause the alcohols in the adhesive to melt the chip a bit. This has never happened to me nor anyone that I know who has repaired a chip, but I did read it somewhere. Just a FYI mainly. Personally, I wouldn't try and rough up the ends to help the adhesive to stick better. This would cause the pieces to not adhere together as they separated. I'm positive that others on this forum will be of great help also.

Good Luck,

Rick