LIST OF TEXT FKJUKES 



Fig. 1. Pycnometer 



,, 2. Basket of platinum wire for holding 

 stone in determination of specific 

 gravity ... . . 



,, 3. Ordinary balance, with arrangement 

 for hydrostatic weighing 



„ 4. Bench for use in hydrostatic weigh- 

 ing with an ordinary balance 



., 5. Westphal's balance for determining 

 the specific gravity of solids 



,, fi. Jolly's spring-balance for deter- 

 mining specific gravity . 



„ 7. Westphal's balance for determining 

 the specific gravity of liquids 



,, X. Cleavage of calcite . 



,, 9. Refraction of light on passing into a 

 precious stone 



„ 10. Refraction of light on passing out of 

 a precious stone 



., 11. Total reflection 



„ 12. Total reflection in diamond when 

 surrounded by air . 



,, 13. Total reflection in diamond when 

 surrounded by methylene iodide . 



„ 14. Path of a ray of light through a plate 

 with parallel sides 



„ 16. Path of a ray of light through a 

 prism 



„ 16. Dispersion of light . 



„ 17. Dispersion of light by a plate with 

 parallel sides ... 



„ 18. Dispersion of light by a prism. For- 

 mation of the spectrum of white 

 light 



,, 19. Path of the rays of light through a 

 prism 



„ 20. Path of a ray of light in a brilliant 



„ 21. Double refraction of a ray of light . 



,, 22. Path of light through a doubly re- 

 fracting plate 



„ 23. Double refraction of calcite or doubly 

 refracting spar .... 



Path of light through a doubly re- 

 fracting prism . . 48 

 Path of light through a doubly re- 

 fracting prism ... 49 

 . Images of a flame observed through 



a doubly refracting stone 49 



. Images of a flame observed through 



a singly refracting stone . 49 



Polariscope for observation in 



parallel light . . 50 



The dichroscope . . 60 



Brilliant (triple-cut) . . 74 



Rosette . . 77 



— .f. Crystalline forms of diamond 



120, 121 

 Actual sizes of octahedral crystals 



of diamond of 1 to 1000 carats . 12(1 

 Diamond-fields of India . 144 



Diamond-fields of Brazil . 156 



Diamond-fields of the Diamantina. 



district, Brazil . . 157 



Occurrence of diamond in the Serra 



da Cincora, Bahia . .172 



Occurrence of diamond in South 



Africa . . . .181 



Diamond mines at Kimberley . . 183 

 Diagrammatic section through the 



Kimberley mine . . . 189 



Section through the Kimberley mine 200 

 Section through the De Beer's mine 201 

 Diamond-fields of the Island of 



Borneo 217 



Diamond-fields of New South Wales 222 

 Actual size of rose diamonds of 1 to 



50 carats . . . 241 



Directions of least hardness on the 



facets of a biilliant . 244 



First stage in the development of a 



brilliant from an octahedron . 244 



The " Great Table," a large Indian 

 diamond mentioned by Tavernier 250 



