1. Native Elements Metals gold, silver, copper, platinum Semimetals
[arsenic, antimony, bismuth]
Non-metals
sulfur, diamond, graphite

2. Primary gold with quartz Secondary gold

3. Dentritic silver
Dentritic silver on cerussite (PbCO3)

4. Copper
Dendritic copper
Copper-Zinc alloy = brass
Copper-Tin alloy = bronze

5. Summary of the Gold-group
Au, Ag, Cu
Minerals are isostructural = cubic closest packing
Isometric, point group 4/m32/m
Au and Ag identical atomic radius = complete solid solution
The gold-silver solid solution is called electrum
Similar physical properties:
Rather soft
Malleable and ductile
Metallic luster
Hackly fracture
Low melting point
High densities

6. Iron Group
platinum, iron
Native iron has two polymorphs,
kamacite (α-Fe) which is body-centred cubic and
taenite (γ-Fe) which is face-centred cubic

7. Kamacite and Taenite

8. Cubic close packing : a smaller section of the ABC stacking
(face-centred cubic) A B C A
This can be used as one unit cell of the structure

9. Platinium crystals
Platinium nugget

10. Arsenic (botryoidal, with calcite crystals)

11. Antimony

12. Dendritic bismuth
Massive bismuth

13. Sulfur
Sulfur

14. van der Waals bonds
S8 rings in sulfur

15. Diamond

16. Diamond-graphite structures

17. Graphite

18. Diamond-graphite structures

19. Fullerene, C60
in shungite, black rocks
with high C-contents