160 REPORT Oi^ NATIONAL MUSEUM, 1899. 



IV. Oxides — Continued. 



10. INIanganese oxides — Continued. Page. 



Braunite - "- 254 



Polianite - 254 



Pyrolusite 254 



Manganite 254 



Psilonielane 255 



Wad or l)og manganese 255 



V. Carbonates: 



1. Calcium ('arl)onate 258 



Calcite; calc spar; Iceland spar 258 



Chalk - 262 



Limestones; mortars; and cements 264 



Portland cement 266 



Roman cement 268 



Playing marbles 270 



Lithographic limestones 270 



2. Dolomite 274 



3. Magnesite 275 



4. Witherite 279 



5. Strontianite 279 



6. Rhodochrosite ; dialogite - 280 



7. Natron, the nitrum of the ancients 280 



8. Trona; urao 281 



VI. Silicates: 



1 . Feldspars 281 



2. Micas - - - 283 



3. Asbestos - 296 



4. Garnet 307 



5. Zircon 308 



6. Spodumene and petalite 308 



7. Lazurite; lapis lazuli; or native ultramarine 309 



8. Allanite; orthite 311 



9. Gadolinite 313 



10. Cerite 314 



11. Rhodonite 314 



12. Steatite; talc; and soapstone 315 



13. Pyrophyllite; agalmatolite; and pagodite 322 



14. Sepiolite; meerschaum 323 



15. Clays 325 



VII. Niobates and tantalates: 



1. Columbite and tantalite 353 



2. Yttrotantalite 354 



3. Samarskite 354 



4. Wolframite and Hiibnerite 355 



5. Scheelite 356 



VIII. Phosphates: 



1. Apatite; rock phosphates; guano, etc 356 



2. Monazite 383 



3. Vanadinite - 387 



4. Descloizite 388 



5. Amblygonite 390 



6. Triphylite and lithiophilite 391 



