A Geoscience Digital Image Library
A Geoscience Digital Image Library
| Title | Calcite with “butterfly twin” |
|---|---|
| Description | This sample of clear calcite is about 6 cm tall. The right and left halves of the calcite are two different crystal domains that have grown together forming a “butterfly twin.” The top of this crystal shows a “re-entrant angle” where intersecting crystal fces point toward the center of the crystal. Re-entrant angles do not form without twinning. |
| Location | England. Near Cumberland. |
| Photographer | Darla Sondrol. 2001-06-11. |
| Collection | University of North Dakota Mineralogy Collection #653. |
| Key words | calcite, butterfly twins, England |
| Tech details | 398 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. |
| GeoDIL number | 682 |
 | |