A Geoscience Digital Image Library
A Geoscience Digital Image Library
| Title | Quartz, amethyst |
|---|---|
| Description | Amethyst, a variety of quartz (SiO2) has been found in siliceous volcanics, occurring as macroscopic crystals and drusy coverings inside of agate lined amygdaloidal cavities or vugs, often forming geodes. Amethyst also occurs in quartz veins. The purple color of amethyst is due to small amounts (approximately 40 parts per million) of iron (Fe4+) impurities at specific sites in the crystal structure of quartz. |
| Location | Brazil. Near Minas Gerais. |
| Photographer | Darla Sondrol. 2002-03-22. |
| Collection | Ward’s Classroom Collection of Gem Minerals #13. |
| Key words | amethyst, quartz, Brazil |
| Tech details | 345 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. |
| GeoDIL number | 2522 |
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