Size : exact size 17.65x6.77mm (can be used as 18x7mm). It is best quality afghan tourmaline with beautiful light green on one side and light pink on the other. It has a surface line fracture (seen as a tiny silver line) on the pavilion facet.
Size : 15x5.5mm or 5.5x15mm (can be used in 6x15mm or 15x6mm settings). This Bi-Tourmaline is sparkling light pink from one end and colorless from another end. The gemstone is eye clean. The gemstone is far more prettier than the pictures.
A very nice bi-colour Tourmaline Gemstone Color: wide color range, green, blue, yellow, pink, red, brown, colorless. Bi-color is common. Hardness: 7 - 7.5 Refractive index: 1.61 - 1.66 Density: 3.01 - 3.25 Chemical composition: (NaLiCa)(Fe11MgMnAl)3Al6((OH)4(BO3)3Si6O18) Crystal structure: trigonal Origins: Brazil, Madagascar, Namibia, Zambia, Sri Lanka, Russia, USA, Afghanistan. Tourmalines exist in different colors and are known for their bi-color or even tri-color varieties. The most expensive color varieties are intense green, blue and red.Heat treatment is occasionally applied to enhance the color of green or blue crystals. Yellow stones could be irradiated to improve their color or clarity.