 |
MAC main page | Young People site | Poster | Pedagogical Guide | Quiz & Game | Get the Poster | Contact us |
Tourmaline | ||
 | Mineral name: | Tourmaline |
| Formula: | (Na,Ca)(Li,Mg,Al)3(Al,Fe,Mn)6(BO3)3(Si6O18)(OH)4 | |
| Category: | Silicate | |
| Name Origin: | From turamali, a name given to the early gems from Sri Lanka | |
| Uses: | One of the most beautiful gemstones; also used in electronic instrumentation | |
| Diagnostic features: | Rounded triangular cross section of the crystal and conchoidal fracture | |
| Interesting facts: | Gem varieties are ligh coloured: pink, green and blue | |
| PROPERTIES | ||
| Colour: | Black but will vary with composition | |
| Streak: | White | |
| Luster: | Glassy | |
| Hardness: | 7-7.5 | |
| Density: | 3-3.2 | |
| Form: | Hexagonal | |
| For more info on this mineral: | http://mineral.galleries.com/minerals/silicate/tourmali.htm http://www.mindat.org/min-4003.html http://en.wikipedia.org/wiki/Tourmaline | |
| THIS SAMPLE: | ||
| Name: | Tourmaline | |
| Size: | Crystal 6 cm tall | |
| Came from: | Grady Lake area | |
| Province: | Northwest Territories | |
| Collection of: | Brad Wilson | |
| Photography by: | Brad Wilson | |
