What Are AB Drills/Diamonds?
AB is short for Aurora Borealis. This refers to the solid colour diamond drills with a beautiful Aurora Borealis rainbow coat that gives it an opalescent shine on the surface. The appearance can differ, it can be a shiny soft pearl-like coating to a strong dual-colour reflection.
They are used to highlight parts of the diamond painting pattern adding dazzling and mesmerizing effects to the art, just like the northern light it got its name from

This is the comparison of the regular diamonds & Aurora Borealis:

This picture is showing AB drills included in a diamond painting to give a better effect:







