Gemstone treatment
Fracture Filling, Corundum
Surface-reaching fractures may show flash effects, residue, bubbles, or glassy material. The stone may look cleaner than its fracture network should allow.
01
What to look for
Surface-reaching fractures may show flash effects, residue, bubbles, or glassy material. The stone may look cleaner than its fracture network should allow.
02
What it means
Fracture filling improves apparent clarity in corundum. Lead-glass-filled ruby is the most important commercial example, but other fillers can occur.
03
Expert move
Tilt the stone under darkfield and side lighting. A flash limited to a fracture plane is the main warning sign.