A Geoscience Digital Image Library
A Geoscience Digital Image Library
| Title | Bournonite |
|---|---|
| Description | Bournonite, CuPbSbS3, (copper lead antimony sulfide), is also called “cog wheel ore” because of the cog wheel shape that the twinned crystals form. Twinning is common in bournonite and if a crystal repeatitively twins it can form a type of twin called a trilling. The trilling is composed of four “twins” or crystals connected in a plane and forms a wheel with a jagged edge that resemble the teeth of a cog wheel. Not all specimens show this type of twinning however. |
| Location | USA ▹ Montana. Near Butte. |
| Photographer | Darla Sondrol. 2001-07-18. |
| Collection | University of North Dakota Mineralogy Collection #262. |
| Key words | Bournonite, Montana |
| Tech details | 570 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. |
| GeoDIL number | 1273 |
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