PLATE XX. 
Figs. 1—3.—Galena. Sulphuret of Lead. 
1. Galena, hexaliedral or simple sulpliuret of lead, primary form, the cube on quartz, from Derbyshire. 
2. The same , the cube, with truncation of the edges (rhombic dodecahedron), and of the angles (octahedron), from 
Neudorf in the Harz. 
3. The same , the cube (H), octahedron (0), rhombic dodecahedron (D), and pyramidal octahedron, double truncation of 
the angles of the cube (I), from Neudorf. 
Figs. 4—8.—White Lead Ore, Cerusite. 
4. White Lead Ore, carbonate of lead, rhombic tables, united as twins, on galena, from Przibram in Bohemia. 
5. The same, rhombic octahedron, with truncation of the acute lateral edges, the hexagonal double pyramid, from 
Badenweiler in Upper Baden. 
6. The same , rhombic prism, primary form, with truncation of the acute lateral edges (the hexagonal prism), and of 
all the basal edges (combination with the hexagonal pyramid), from the same locality. 
7. The same , with predominance of each of the two lateral and basal planes. 
8. The same , the same form, six crystals aggregated in a stellate figure, from Badenwmiler. 
Figs. 9—11.—Anglesite, Sulphate of Lead. 
9. Anglesite , a right rhombic prism, the primary form, with truncation of the basal angles (oblong octahedron) from 
Iglesias in Sardinia. 
10. The same, a rhombic table, with truncation of the obtuse angles, from the same locality, 
11. The same , combination of the rectangular and rhombic octahedron with the rhombic prism, whose acute lateral edges 
are truncated. 
Figs. 12— 15. —Pyromorphite,, Phosphate of Lead, Auseniate of Lead. 
12. Yellow Arseniate of Lead, or Kampylite, in barrel-shaped curved crystals, from Caldbeck in Cumberland. 
13. Pyromorphite Phosphate of Lead, primary form, a hexagonal prism, from Ems in Nassau. 
14. Yellow Arseniate of Lead, hexagonal double pyramid, with truncation of the vertex, from Joachimsthal in Bohemia. 
15. The same, hexagonal prism, with truncation of the basal edges, from the same locality. 
Fig. 16. —Molybdate of Lead, Yellow Lead Ore. 
16. Yellow Lead Ore, Wulfenite, in square tables, in part with truncation of the basal edges (square octahedron), trom 
Bleiberg in Carinthia. 
Fig. 17. —Chromate of Lead, Red Lead Ore. 
17. Red Lead Ore, Crocoisite , tabular, and in oblique rhombic prisms, from Beresowsk in Siberia. 
Figs. 18—22.—Tin Ore, Oxide of Tin. 
18. Cassiterite , Tin Ore, in quadratic prisms, partly with truncation of the lateral and basal edges, from Ehrenfriedersdorf. 
19. The same , twins of quadratic lentils, from Altenberg in Saxony. 
20. The same, quadratic prism, with truncation of the basal and lateral edges, and of all the angles, from St. Agnes in 
Cornwall. 
21. The same, quadratic octahedron with the quadratic prism, from the same locality. 
22. Wood Tin , fibrous oxide of tin, also from the same locality. 
Figs. 23—27.— Zinc Ores. 
23. Blende , the primary form, the rhombic dodecahedron with the octahedron, from Ivapnik. 
24. Foliated red Oxide of Zinc, wdth zinc iron or e, franJclinite, in regular octahedrons, tvith truncation of the edges, 
imbedded in compact zinc ore, from Franklin in New Jersey. 
25. Carbonate of Zinc, Galmey, or Calamine, drusy, in aggregations of rhombohedrons of compact calamine, from Alten¬ 
berg near Aachen. 
26. The same, the middle and obtuse rhombohedron. 
27. Siliceous Oxide of Zinc, a right rhombic prism, with truncation of the angles and of the obtuse lateral edges, from the 
same locality. 
