2a. Orthoclase. Anhydrous silicate of alumina with varying amounts of lime, potash, or soda and rarely barium. 2b. Microcline. „ 2c. Albite. „ 2d. Oligoclase. „ 2e. Andesite. „ 2f. Labradorite. „ 2g. Bytownite. „ 2h. Anorthite. „ 3. The Amphiboles: 3a. Hornblende. Anhydrous silicates of lime and magnesia with iron and alumina in the dark varieties. 3b. Tremolite. „ 3c. Actinolite. „ 3d. Arfvedsonite. „ 3e. Glaucophane. „ 3f. Smaragdite. „ 4. The Monoclinic Pyroxenes: 4a. Malacolite. Anhydrous silicates of magnesia and lime with alumina and iron in the dark varieties. 4b. Diallage. „ 4c. Augite. „ 4d. Acmite. „ 4c. Aegerite. „ 5. The Rhombic Pyroxenes: 5a. Enstatite (bronzite). Silicates of magnesia and iron. 5b. Hypersthene. „ 6. The Micas: 6a. Muscovite. Anhydrous silicates of alumina with potash, soda, and iron. 6b. Biotite. „ 6c. Phlogopite. „ 7. Calcite, 8. Dolomite. 9. Gypsum. 10. Olivine. 11. Beryl. 12. Tourmaline. 13. Garnet, variable common form. 14. Vesuvianite. 15. Epidote. 16. Zoisite. 17. Allanite. 18. Andalusite. 19. Staurolite. 20. Fibrolite. 21. Cyanite. 22. Scapolite. 23. Apatite. 24. Elaeolite and Nepheline. 25. Leucite. 26. Cancrinite. 27. The Sodalite Group: 27a. Sodalite. 27b. Haüyn (noseau). 28. Zircon. 29. Chondrodite. 30. Cordierite. 31. Topaz. 32. Corundum. 33. Titanite (sphene). 34. Rutile. 35. Menaccanite. 36. Magnetite. 37. Hematite. 38. Chromite. 39. The Spinels: 39a. Pleonast. 39b. Picotite. 40. Pyrolusite. 41. Halite (common salt). 42. Fluorite. 43. The Elements: 43a. Graphite. 43b. Carbon. 43c. Iron. 43d. Copper. 44. The Metallic Sulfids: 44a. Galena. 44b. Sphalerite. 44c. Pyrrhotite. 44d. Marcasite. 44e. Pyrite. 44f. Chalcopyrite. 44g. Arsenopyrite. SECONDARY MINERALS. 1. Quartz: 1a. Chalcedony. 1b. Opal. 1c. Tridymite. 2. Albite.