REFRACTION AND BIREFRINGENCE OF MINERALS 423 



Mineral 



Actinolite 



Aegirite 



Albite 



Allanite 



Almandite 



Alunite 



Ana] cite 



Andalusite 



Andesine 



Anhydrite 



Anomite (Var. Biotite) 



Anorthite 



Anorthoclase 



Antophyllite 



Antigorite 



Apatite 



Apophyllite 



Aragonite 



Astrophyllite 



Augite 



Axinite 



Barkevikite 



Biotite 



Breislakite (Var. Ilvaite) 



Breunnerite 



Brewsterite 



Bronzite (betw. Enstatite and Hypersthene) 



Brookite 



Brucite 



Bytownite 



Calcite 



Cancrinite 



Carpholite 



Cassiterite 



Celsian 



Chabazite 



Chalcedony 



ChiastoHte (see Andalusite) 



Chloritoid (see Ottrelite) 



Chondrodite 



Chrysolite (see Olivine) 



Clinozoisite 



Clinohumite 



Indices of Refraction 



1 .612 

 1 .600 



1-763 

 1-529 

 1.78 

 ? 

 1 .809 



1-592 

 1.487 



1 .632 



1-549 

 1-570 



1-575 

 1-523 

 1-633 

 1 .629 

 1.490 

 1.560 

 1 .629 

 1 .641 

 1-536 

 1.528 



1-534 

 1.678 

 1.688 

 1 .712 

 1 .672 

 1.687 



I -541 

 1.580 



1-504 



1-528 



? 



2-583 

 1.580 

 1 .561 

 1.486 

 1.499 

 1 .627 

 1.979 

 2.012 

 1.584 



1-5 

 1 .46 



1-533 



1 .607 



1. 714 

 ? 



1 .627 



1. 616 



1.799 



1-532 

 ? 



1.68 

 1-572 



1.638 



1-553 

 1-576 



1.584 

 1.528 

 1 .642 

 1.630 



1 .502 



1-570 

 1 .631 

 1.645 



1-534 

 1 .676 

 1.689 



1-703 

 1 .701 

 1. 717 

 1.678 

 1.707 



? 



? 

 1.589 



1. 717 

 1-45 



2.586 



1-559 

 1.564 

 1.658 

 1.522 



? 

 2.080 

 2.108 



1-587 

 ? 



? 

 1-536 



1 .619 



1 .716 

 1 .670 



V 



1.639 

 1.628 

 1. 813 



1-539 



? 



? 



1.643 



1-555 

 1 .614 



1.529 



1-657 

 1 .640 

 1. 511 

 1-571 



1.694 

 1-733 

 1-713 

 1-733 

 1. 681 

 1.708 

 1.580 

 1.638 

 1.589 



2.741 

 1.569 



1-594 

 1-544 

 1.639 



1.724 

 ? 



Maximum 



Bi- 

 refringence 



0.027 

 0.028 

 0.040 

 O.OIO 



0.032 



0.020 



O.OII 



0.006 

 0.044 



0.013 



0.006 

 0.024 



O.OII 



0.022 



O.OII 



0.002 

 0.004 

 0.002 



0-153 



o. 160 



0-055 

 0.025 



0.021 

 0.009 

 0.021 



0.039 

 0.058 

 0.085 



0.189 

 0.012 



0.158 



0.021 

 0.008 

 o. 172 

 0.023 

 0.022 



O. lOI 



0.096 



O.OIO 



0.003 

 0.002 

 o .011 



0.030 

 0.010 



