A Geoscience Digital Image Library
A Geoscience Digital Image Library
| Title | Tourmaline on quartz |
|---|---|
| Description | Tourmaline is a group named for several different, but closely related minerals. Tourmalines are piezoelectric which means that when a crystal is heated or compressed (or vibrated) a different electrical charge will form at opposite ends of the crystal (an electrical potential). Conversely if an electrical potential is applied to the crystal, it will vibrate. They are also pleochroic which means that the crystal will look darker in color when viewed down the long axis of the crystal than when viewed from the side. The four most common and well known tourmalines are distinguished by their color and transparencies. Elbaite Na(Li,Al)3Al6Si6O18(BO3)3(OH)4, is the gemstone tourmaline and comes in many varied and beautiful colors. The photograph is of an elbaite. Schorl, dravite and uvite are the three other most common types. |
| Location | Brazil. Larve de Pederneira, M.G. |
| Photographer | Shannon Heinle. 2001-10-22. |
| Collection | Dexter Perkins Mineral Collection. |
| Key words | tourmline, elbaite, piezoelectric, pleochroic |
| Tech details | 435 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. |
| GeoDIL number | 1686 |
 | |