Native Elements
Comparatively few of the elements are found in the native state, and moreover, these are in general rare in occurrence. The elements occurring as minerals may be divided into three classes:
- Nonmetals
- Semimetals
- Metals
The important minerals among the nonmetals are diamond, graphite and sulfur. The semimetals – tellurium, arsenic, antimony and bismuth- belong together in a crystal group, all of them showing rhombohedral crystals with closely agreeing fundamental angles. The Gold Group is the most important one among the metals, including the isometric minerals, - gold, silver and copper. Another group contains the rare metals platinum and iron.
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