Page 439 - Copper and Bronze in Art: Corrosion, Colorants, Getty Museum Conservation, By David Scott

TABLE 2 CRYSTAL SYSTEMS AND REFRACTIVE INDICES

MINERAL NAME CRYSTAL SYSTEM REFRACTIVE INDICES (Rl)
antlerite orthorhombic α 1.726 β 1.739 γ 1.788
atacamite orthorhombic α 1.831 β 1.861 γ 1.880
aurichalcite orthorhombic α 1.658 β 1.746 γ 1.751
azurite monoclinic α 1.73 β 1.838 γ 1.758
botallackite monoclinic α 1.775 β 1.800 γ 1.846
brochantite monoclinic α 1.728 β 1.771 γ 1.800
calumetite uncertain α 1.666 β 1.690 γ 1.690
chalcocite hexagonal opaque
chalconatronite monoclinic α 1.483 β 1.530 γ 1.576
chrysocolla orthorhombic α 1.575 β 1.597 γ 1.598
clinoatacamite monoclinic α 1.842 β 1.842 γ 1.848
connellite hexagonal ω 1.736 8 1.756
cornetite orthorhombic α 1.762 β 1.820 γ 1.825
covellite hexagonal opaque ω ι.45 (Na)
cuprorivaite tetragonal α 1.589 β 1.627 γ 1.628
dioptase rhombohedral β 1.656
djurleite monoclinic opaque
enargite orthorhombic α 2.82 β 2.93 γ 3.14
eriochalite orthorhombic α 1.646 β 1.685 γ 1.745
geerite cubic opaque
georgeite amorphous R I 1.593
gerhardtite orthorhombic α 1.703 β 1.713 γ 1.722
langite monoclinic α 1.654 β 1.713 γ 1.722
libethenite orthorhombic α 1.703 β 1.746 γ 1.789
linarite monoclinic α 1.809 β 1.838 γ 1.859
malachite monoclinic α 1.655 β 1.875 γ 1.909
melanothallite orthorhombic not known
moolooite orthorhombic not known
namuwite hexagonal R I 1.577
nantokite cubic R I 1.93
paratacamite rhombohedral ω 1.842 £ 1.848
phthalocyanine blue R I 1.38
posnjakite monoclinic α 1.624 β 1.679 γ 1.705

A P P E N D I X C
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