Table 403 



index of refraction 



363 



Selected Monorefringent or Isotropic Minerals 



The values are for the sodium D line unless otherwise stated and are arranged in the order of increasing indices 

 Selected by Dr. Edgar T. Wherry from a private compilation of Dr. E. S. Larsen of the U. S. Geological Survey. 



Mineral. 



Villiaumite 



Crvolithionite. . . 



Opal 



Fluorite 



Alum 



Sodalite 



Cristobalite 



Analcite 



Sylvite 



Noselite 



Hauynite 



Lazurite 



Leucite 



Pollucite 



Halite 



Bauxite 



Pharmacosiderite 



Spinel 



Berzeliite 



Peiiclasite 



Grossularite .... 



Helvite 



Pyrope 



Arsenolite 



Hessonite 



Pleonaste 



Almandite 



Hercynite 



Gahnite 



Spessartite 



Lime 



U varovite 



Andradite 



Microlite 



Nantokite 



Pyrochlore 



Schorlomite 



Percy lite 



Picotite 



Eulytite 



Cera rgy rite 



Mosesite 



Chromite 



Senarmontite. . . 



Embolite 



Manganosite. .. . 



Bunsenite 



Lewisite 



Miersite 



Bromyrite 



Dysanalite 



Marshite 



Franklinite 



Sphalerite 



Perovskite 



Diamond 



Eglesionite 



Hauerite 



Aiabandite 



Cuprite 



Formula. 



NaF 



3NaF. 3 LiF.2AlF 3 



Si0 2 .nH 2 



CaF 2 



K2O.AI2O3.4SO3.24H2O 



3Nao0.3AI 2 3 .6^iO,.2NaCl 



SiG 2 



Na.,O.Al.,0|.4SiO,.2H 2 



KC1 



5 Na.,0. 3 Al : ,0 :l .6Si0,,.2S03 



Like preceding + CaO 



4 NanO.^Al,0 3 .6SiO,.Na.,S 6 



K-O.AUOs^SiO, 



2Cs,0.2AL0 3 .9SiO.,.H.,0 



NaCl 



Al 2 3 .nH,0 



3Fe,0,.2As 2 6 .3K 2 0. S H 2 



MgO.AUOj 



3(Ca, Mg, Mn)O.As 2 5 



MgO 



3Ca0.Al 2 03.3Si0 2 



3(Mn, Fe)0.3Be0.3Si0 2 .MnS 



3Mg0.Al 2 0a.3Si0 2 



As 2 03 



3CaO.(Al. Fe) 2 03.3Si02 



(Mg, Fe)0.Al 2 0» 



3Fe0.Al 2 3 .3Si0 2 



FeO.AbOs 



ZnO.AljOa 



3Mn0.Al 2 3 .3Si0 2 



CaO 



3CaO.Cr 2 3 .3Si0 2 



3Ca0.Fe 2 03.3Si0 2 



6Ca0.3Ta 2 0i.Cb0F 3 



CuCl 



Contains CaO, Ce 2 03, Ti0 2 , etc. 



3 CaO.(Fe, Ti) 2 3 .3(Si, TiJOi 



PbO.CuCl2.H2O 



(Mg, Fe)0.(Al, Cr)20 3 



2Bi 2 3 .3Si0 2 



AgCl 



Contains Hg, NH«, CI, etc. 



FeOCr 2 3 



SteOu 



Ag(Br, CI) 



MnO 



NiO 



sCaO,2Ti0 2 .3Sb 2 Os 



CuI.4AgI 



AgBr 



Contains CaO, FeO, Ti0 2 , etc. 



Cul 



(Zn, Fe, Mn)0.(Fe, Mn) 2 Os 



(Zn, Fe)S 



CaO.Ti0 2 



C 



Hg0.2HgCl 



MnS 2 



MnS 



Cu 2 



Index of 



refraction, 



X = 0.S89/X. 



328 



339 



. 406-1 . 440 

 ■434 



■ 4S6 

 •483 

 .486 

 .487 

 .490 

 •495 

 .496 

 .500 ± 



5°0 

 .525 

 544 



■ 570 * 

 .676 



■ 723 * 

 .727 



■ 736 

 ■736 



■ 739 



• 74S 



■ 755 



• 763 

 .770 =»= 



■ 778 

 .800 ± 

 .800 ± 

 .811 

 .830 

 .838 

 .857 

 ■925 



• 930 



.960-2.000 

 .980 



2.050 



2.050 =*= 



2.050 



2.061 



2.065 



2.070 



2.087 



2.150 ± 



2. 160 



2 . 18 (Li light) 



2. 200 



2. 200 



2253 



2.330 



2.346 



2 . 360 (Li light) 



2.370-2.470 



2.380 



2.419 



2.490 (Li light) 



2 . 690 (Li light) 



2. 700 (Li light) 



2.849 



Smithsonian Tablec- 



14 



