A Geoscience Digital Image Library
A Geoscience Digital Image Library
| Title | Corundum |
|---|---|
| Description | Corundum, Al2O3, comes in many colors. Sometimes it is gemmy and has value as a gemstone (ruby or sapphire), but the crystals in this sample are not clear or bright colored enough to be gems. Ideal corundum crystals are hexagonal in cross section, and elongated perpendicular to the hexagons. That symmetry can be seen in the large crystal (3 cm long) in this photo. Besides corundum, this specimen also contains white plagioclase and black biotite. It was purchased at a rock and mineral show and its provenance is unknown. |
| Photographer | Neil Kadrmas. 2001-05-01. |
| Collection | University of North Dakota Mineralogy Collection. |
| Key words | corundum |
| Tech details | 510 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. |
| GeoDIL number | 447 |
 | |