I was most fortunate to be in the hunt for different colors in tourmaline, when Mozambique began to produce cuprian tourmaline. Then it was years before the copper bearing nature of the deposit was revealed in a reverse Alexandrite color change tourmaline, I sent to the GIA to be analyzed. To follow up on the cuprian tourmaline adventure, that has pretty much ended, I purchased a spectrometer. With this instrument I analyzed all my gemstones for copper and found quite a few that I did not buy as cuprian and did not realize contained copper, based on their color. I also verified the cuprian nature of the stones I purchased as copper bearing and satisfied myself that some colors, usually shades of purple, are definitively copper bearing.
The posted standard round brilliant has a more saturated color than many yellow greens. It is also quite bright, but I had no idea is contained copper until I tested it with my spectrometer. It is included, but only slightly, like most cuprian tourmaline from Mozambique are. I am not sure that copper has much effect on the color of this gemstone, but the droplet of color is bright and very attractive so let it be. It weighs 1.46 carats.