tourmaline
Tourmaline (English: tourmaline), commonly known as tourmaline, transliteration for tourmaline, one of the natural colorful gem. Tourmaline with quartz and other piezoelectric effects. Origin includes Brazil, Sri Lanka, Madagascar and so on. Currently in the global jewelry market, Para Yiba tourmaline and other colored tourmaline by collectors attention. Hardness between 7-7.5, the refractive index of about 1.62-1.64 between the refractive index difference of about 0.020. As Paraiba contains copper elements, it will show a natural and bright blue-green, even in natural light or no light source environment, will emit a neon color, which can be said to be the most One of the attractive features. ...