525 



TABLE 546.— INDEX OF REFRACTION OF SELECTED UNIAXIAL MINERALS 



(concluded) 



Uniaxial negative minerals (continued) 



Mineral Formula 



Apatite 9CaO-3P 2 6 -Ca(F, Cl) 2 



Calcite CaO-C0 2 



Gehlenite 2CaO-Al 2 0*-Si0 2 



Tourmaline Contains Na 2 0, FeO, A1 2 3 , B 2 3 , Si0 2 , etc. 



Dolomite CaO-MgO-2C0 2 



Magnesite MgO • C0 2 



Pyrochroite MnO ■ H 2 



Corundum A1 2 3 



Smithsonite ZnO'C0 2 



Rhodochrosite ... MnO-C0 2 



larosite K 2 0-3Fe 2 3 -4S0 3 -6H 2 



Siderite FeO-C0 2 



Pyromorphite .... 9PbO-3P 2 5 -PbCl 2 



Barysilite 3PbO-2Si0 2 



Mimetite 9PbO-3As 2 CvPbCl 2 



Matlockite PbO-PbCl 2 



Stolzite PbO-W0 3 



Geikielite (Mg, Fe)OTi0 2 



Vanadinite 9PbO-3V 2 5 -PbCl 2 



Wulfenite PbOMoO. 



Octahedrite Ti0 2 



Massicotite PbO 



Proustite 3 Ag 2 S • As 2 S 3 



Pryargyrite 3Ag 2 S • SbjSs 



Hematite Fe 2 3 



TABLE 547.— INDEX OF REFRACTION OF MISCELLANEOUS LIQUIDS 

 (see also Table 551), LIQUEFIED GASES, OILS, FATS, AND WAXES 



Temp 



Substance °C 



Oils: 



Lavender 20 



Linseed 15 



Maize 15.5 



Mustard seed . . 15.5 



Neat's foot 15 



Olive 15.5 



Palm 60 



Peanut 15.5 



Peppermint .... 20 



Poppy 15.5 



Porpoise 25 



Rape (Colza) .. 15.5 



Seal 25 



Sesame 15.5 



Soya bean 15.5 



Sperm 15.5 



Sunflower .... 15.5 



Tung 19 



Whale 40 



Fats and Waxes : 



Beef tallow 40 



Beeswax 75 



Carnauba wax . 84 



Cocoa butter . . 40 



Lard 40 



Mutton tallow. . 60 



Index for D 

 0.589m 



1.464 -1.466 



1.4820-1.4852 



1.4757-1.4768 



1.4750-1.4762 



1.4695-1.4708 



1.4703-1.4718 



1.4510 



1.4723-1.4731 



1.464 -1.468 



1.4770 



1.4677 



1.4748-1.4752 



1.4741 



1.4742 



1.4760-1.4775 



1.4665-1.4672 



1.4739 



1.503 



1.4649 



1.4552-1.4587 

 1.4398-1.4451 

 1.4520-1.4541 

 1.4560-1.4518 

 1.4584-1.4601 

 1.4510 



SMITHSONIAN PHYSICAL TABLES 



