Blue ground, 10, 47 -- -- diamantiferous, 18, 19
Boart, 81, -- combustion temperature of, 90 -- density of, 93
Bultfontein Mine, 14 -- -- characteristics of diamond from, 64
Carbon, boiling and melting point of, 110 -- combustion temperature of, 90 -- critical point of, 110 -- density of, 93 -- dissolved in iron, 116 -- volatilisation of, 115
Characteristics of diamonds from the different mines, 64
Chromate of lead, refractive index of, 103
Chrome diopside, 71 -- iron, 20 -- -- ore, 71 -- -- -- density of, 93
Combustion of diamond, 89 -- temperatures of diamond, boart, graphite, and carbon, 90
De Beers Consolidated Mines, 7, 33 -- -- floors at Kenilworth, 47 -- -- Mine, 14, 24, 34 -- -- -- characteristics of diamonds from, 64 -- -- strong-room, 74
Density of diamond, 57, 93 -- of graphite, 83, 93 -- of stones accompanying diamond, 70, 71, 93, 95
Dewar, Sir J., conversion of diamond into graphite, 123
Diamond, absorption spectrum of, 101 -- and polarised light, 104 -- a new formation of, 122 -- ash of, 82, 89 -- collector, automatic, 56 -- combustion of, 89 -- -- temperature of, 90 -- converted into graphite, 100 -- density of, 57, 93 -- etched by burning, 88 -- explosion of, 120 -- genesis of the, 115 -- in meteors, 134 -- in Röntgen rays, 107 -- matrix of, 67 -- natural formation of, 127 -- Office at Kimberley, 73 -- physical and chemical properties of, 89 -- pipes or craters, 18 -- radio-activity of, 109 -- refractive index of, 103 -- Trade Act, 36 -- triangular markings on, 87 -- tribo-luminescence of, 100
Diamonds, coloured or fancy, 62, 82 -- Maskelyne on, 1 -- noteworthy, 76 -- phosphorescence of, 96 -- produced, weight, value of, 35 -- yield of, from De Beers, 60
Dutoitspan Mine, 14, 23 -- -- characteristics of diamonds from, 64
Frank Smith Mine, 15 -- -- -- characteristics of diamonds from, 66
Graphite, 81, 83 -- combustion temperature of, 90 -- conversion of diamond into, 100 -- density of, 93 -- diamonds coated with, 99
Grease, collecting diamonds by aid of, 57
Iron a solvent for carbon, 116 -- ore, density of, 93 -- pyrites, 20
Jagersfontein diamond, 79 -- Mine, 14 -- -- characteristics of diamonds from, 68
Kamfersdam Mine, 15 -- -- characteristics of diamonds from, 66
Kimberley, 6 -- blue ground, 10 -- mines, 14, 23, 34 -- Mine in old days, 25 -- -- at the present day, 34 -- -- characteristics of diamonds from, 63 -- shales, 15 -- West Mine, 15 -- -- -- characteristics of diamonds from, 66