REFRACTION AND BIREFRINGENCE OF MINERALS 425 



Mineral 



Indices of Refraction 



Maximum 



Bi- 

 refringence 



Heulandite 



Green Hornblende 



Basaltic Hornblende 



Hortonolite 



Humite 



Hussakite 



Hyalite 



Hyalophane : Or'^Ce^ 



Or7Ce3 



Hydrargillite 



Hydronephelite 



Hydrophane 



Hypersthene 



Ilvaite 



Jadeite 



Kaolin 



Kornerupine (see Prismatine) 



Labradorite 



Laumontite 



Lavenite 



Lawsonite 



Lazulite 



Leucite 



Leucophanite 



Lievrite (see Ilvaite) 



Lussatite 



Magnesite 



Margarite 



Marialite 



Meionite 



Melanite 



Melilite 



Meliphanite 



Mizzonite 



Monazite 



Monticellite 



Mosandrite 



Muscovite 



Natrolite 



Nephelite 



Noselite ; 



Octahedrite 



Oligoclase 



Olivine 



Opal 



Orthite (see Allanite) 



1.498 

 1 .640 

 1.680 

 1.768 

 ? 



1. 816 



1-437 

 1.458 



1-537 

 1.542 



1-535 



1.49 



1.368 



1-451 

 1 .692 

 1. 716 



? 

 ? 



1-54 



1-555 



1-513 



? 



1.665 

 1 .603 

 1.509 

 1-571 



1.446 

 1-515 



1-542 



1-557 

 1-857 

 1 .629 



1-593 

 1.546 

 1.796 

 1.786 

 1.650 

 1 .646 

 1.560 

 1.569 

 1.478 

 1-538 

 1.483 

 1.504 

 2.489 

 1.540 

 1.654 

 1.442 

 1.450 



1.499 

 1.643 



1-725 

 1.792 

 1.643 

 I .721 



1.540 

 1.542 



1-535 



.702 



1.654 



1-558 

 1.524 



1-750 

 1 .669 

 1 .632 

 1.508 

 1-595 



1. 717 

 1 .64 

 1.65 

 1-555 

 1-594 



1.634 

 1 .613 

 1.566 

 1.797 

 1.789 

 1 .662 

 1.649 



1-594 

 1.605 

 1 .482 

 1-543 



.562 



-544 

 .670 



V 



1-505 

 1.656 



1-752 

 1.803 



? 



•542 

 ■547 

 ■558 



1-705 

 1.727 



? 

 ? 

 ? 



1-563 

 1-525 



? 



1.684 

 1.639 



1-598 



1-837 

 1.668 

 1.658 

 1.598 

 1 .612 

 1.492 



1-547 

 1.689 



0.007 

 0.016 

 0.072 

 0-035 

 0.038 

 0.005 



0.005 

 0.005 

 0.023 

 0.012 



0.013 



O.OII 



0.029 

 0.008 



0.008 

 0.012 

 0.030 

 0.019 

 0.036 



O.OOI 



0.027 



0.202 

 0.009 



0.013 



0.037 

 0.005 



0.020 

 0.020 



0.045 

 0.051 



0.018 

 0.012 

 0.038 



0.043 



0.014 



0.005 



0.073 



0.007 



0-035 



