A Geoscience Digital Image Library
A Geoscience Digital Image Library
| Title | Rhyolite porphyry, St. Francois Mountains, Missouri |
|---|---|
| Description | The visible whitish crystals are quartz phenocrysts up to 1-2 mm in size, but most of this sample is so fine grained that minerals cannot be identified. In thin section, identification is only slightly easier, but fine grained quartz and K-feldspar can be seen. This sample 11 cm across. |
| Location | USA ▹ Missouri. St. Francois Mountains. |
| Photographer | Mike Davis. 2001-04-26. |
| Collection | Ward’s University Rock Collection #108. |
| Key words | rhyolite porphyry, Missouri |
| Tech details | 571 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera, 60mm AF Nikon micro lens. |
| GeoDIL number | 416 |
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