Fill the chip with Araldite Glass epoxy.
Use a small piece of masking tape on the edge of the glass in a vertical postion to form a lip to prevent slump.
Cut off most of excess glue with a craft knife before epoxy has fully set, about 6 hours.
After 48 hours level and polish the repair with a Buff & Gloss emery board used for nail manicure.
Big Softy, December 2010