ABOUT tourmaline
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Tourmaline (TUR-mÉ™-leen) is a crystalline boron silicate mineral compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. Tourmaline is classified as a semi-precious stone and the gemstone comes in a wide variety of colors.
| Color | Black to Bluish-Black to deep Brown, while magnesium-rich varieties are Brown to Yellow, and lithium-rich tourmalines are almost any color: Blue, Green, Red, Yellow, Pink, etc. Rarely, it is colorless. |
| Mohs scale hardness | 7.0 - 7.5 |
| Specific gravity | 3.03 - 3.25 |
| Refractive index | 1.62 - 1.64 |
