Oil filling is a common practice in emeralds globally and is acceptable when it comes to astrology. This is restricted however to common baby oil, without any added color. When it comes to coloring agents and semi permanent fillings like epoxy and various others, those tend to lower value and should be avoided. At Navratan, a reliable third party certificate details all there is to know about the gemstone with treatments disclosed. Always check gems with an astrologer for an accurate consultation.