What does fracture filling involve?

• A. Injecting a molten glass substance into surface-reaching feathers or laser drill-holes
• B. Filling with epoxy resin
• C. Coating the surface with lacquer
• D. Removing feathers by polishing

Answer: (A)

Fracture filling is the process of injecting a molten glass‑like substance into surface‑reaching fractures or laser drill holes in a diamond to improve appearance by hiding cracks. The material fills the openings, seals the fracture, and, once it cures, helps to reduce light leakage and make the diamond look clearer. This treatment is aimed at cosmetic enhancement, not structural repair, and it can be sensitive to heat, abrasion, and solvents, so it may not be as durable as the surrounding diamond. In grading reports, this treatment is typically disclosed because it affects how the diamond’s clarity is perceived. The other options describe different practices (epoxy or lacquer applications, or removing feathers by polishing) that do not match the fracture‑filling process.