424 



W. O. HOTCHKISS 



Mineral 



Indices of Refraction 



Clinochlore 



Cordierite 



Corundophilite . . . .' 



Corundum 



Cummingtonite 



Cyanite 



Danalite (see Helvite) 



Datolite 



Diallage (see Diopside, Hedenbergite, 



and Augite) 



Diaspora 



Diopside 



Dipyre (see Mizzonite) 



Disthene (see Cyanite) 



Dolomite 



Dumortierite 



Enstatite 



Epidote 



Epistilbite , 



Eucolite 



Eudyalite 



Fayalite 



Fluorite 



Forsterite 



Gahnite 



Gastaldite 



Gedrite 



Gehlenite 



Gibbsite (see Hydrargillite) 



Glaucophane 



Gmelinite 



Goethite 



Grandidierite 



Grossularite 



Griinerite 



Gypsum 



Hainite 



Harmotome 



Hiortdahlite 



Hedenbergite 



Hauynite 



Helvite 



Hercynite 



1-585 

 1-532 



1-592 



? 



1-758 



? 



1 .712 

 1 .624 



1 .702 

 1.699 

 1. 671 



1-503 

 1.678 

 1.656 

 1.665 



1-730 

 ? 



1. 618 

 1 .614 

 1 .606 

 1.824 



1-434 

 ? 



1-765 

 1.640 



.623 

 .658 



.621 

 .467 

 .464 

 .478 

 ? 



.602 



•744 



•757 

 ? 



.520 

 ? 



-503 



? 



? 



-732 

 .496 

 -504 

 -483 

 •739 

 •749 



7 



-596 



-539 



-599 

 ? 



? 

 1.728 



1 .669 



1-730 

 1. 717 



1 .700 



1.665 



1.674 



1.768 



? 



1.874 



? 



? 

 1.644 



1.639 



1-530 



? 



1.508 



? 

 ? 



1-751 



Maximum 



Bi- 

 refringence 



O.oil 

 0.007 

 0.007 



0.008 



0.016 



0.045 



0.028 

 0.018 

 0.029 



0.179 



O.OII 



0.009 

 0.009 



0.038 



O.OIO 



0.003 

 0.002 

 0.002 



0.050 



0.018 

 0.024 

 0.021 



0.005 



.018 



.009 



.001 

 .002 



0.036 



0.056 



O.OIO 



0.012 



0.005 



0.017 

 0.020 

 0.019 



