A Geoscience Digital Image Library
A Geoscience Digital Image Library
| Title | Harmotome |
|---|---|
| Description | Harmotome is a hydrated barium aluminum silicate. Harmotome is one of the rarer zeolites, but is popular among zeolite and twin collectors. If perfectly formed, a twinned crystal of harmotome can appear to be composed of three prismatic crystals grown through the each others center at nearly 90 degree angles. Zeolites have an openness about their structure that allows large ions and molecules to reside and move around inside the overall framework. The structure contains open channels that allow water and large ions to travel into and out of the crystal structure. The size of these channels controls the size of the molecules or ions and therefore a zeolite like harmotome can act as a chemical sieve. Its chemical formula is BaAl2Si6O16·6H2O. The name comes from the Greek harmos meaning “I combine” and temseis meaning “I cut” alluding to the fact that the pyramid divides parallel to the plane that passes through the terminal edges. |
| Location | Scotland. Near Strontian. |
| Photographer | Shannon Heinle. 2001-02-06. |
| Collection | University of North Dakota Mineralogy Collection #1864. |
| Key words | harmotome, silicate, zeolite |
| Tech details | 221 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. |
| GeoDIL number | 27 |
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