Tommaso Design 8x6mm Oval Genuine Tanzanite Engagement Ring 14kt Gold Metal: 14 kt White Gold. Dimensions: Width: 10.00 mm Length: 8.00 mm This Classic creation is made by the renowned Tommaso Design Studio. Tommaso Design Studio, is a reputable American Family Business based in New York since 1986, uses the highest quality materials, and will proudly stand behind all of its products. Tanzanite: The Alternate Birthstone for September. Tanzanite is a rare blue gem and a popular alternative to blue sapphire. The gemstone was discovered in 1967, and it is mined at only one very small mining location in Tanzania. Additional Stones: (0.04 carat white-diamond, Shape: round-shape, Color: L-M, Clarity: I3, Creation: natural, Treatment: not-treated.)