4.27 Oval Cut Tourmaline Engagement Ring in 14k Yellow Gold4. 27 Oval Cut Tourmaline Engagement Ring in 14k Yellow Gold. This impressive engagement ring features a 4. 27 carat green tourmaline in 14k yellow gold. The bright, forest green hues of the tourmaline are cut into an oval shape that bursts with fire and brilliance. The primary stone is prong set and is nestled between two beautiful . 055 carat baguette diamonds on either side. Two secondary accent diamonds, each weighing . 025 carats finish the