Could be the species, neutral or ionized, indicated by its common chemical symbol. Vacancies are denoted by V Certification: The existence of a reputable gemological certification from a reliable and regarded gem laboratory adds reliability and assurance to the quality of yellow sapphire or almost every other gemstone. Or you https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share