Emerald Oiling: The Refining Process and Its Impact On Pricing
The Use of Oil in the Treatment of Emeralds - JC Esmeraldas - Pre-Consulting, Purchase and Sale of Rough and Polished Stones
Emerald Treatment: Understanding Oil Enhancement and Its Impact on Gem – Lilo Diamonds
Why are natural emeralds oiled? - Annaig's GemStudio
Almost Flawless! Striking Green Colour Emerald from a new location of Afghanistan. No oil. The Colour beats Muzo Emeralds, In video it's difficult to capture the real Colour! : r/Gemstones