List of Gem Refractive Index

Name

Refraction

Double Refraction

Birefringence

Hematite

2.94 - 3.22

Yes

0.28

Diamond

2.417 - 2.419

None

NA

Sphalerite

2.368 - 2.371

None

NA

Cassiterite

1.997 - 2.093

Yes

0.096 to 0.098

Demantoid Garnet

1.88 - 1.94

None

NA

Melanite

1.88 - 1.94

None

NA

Sphene

1.843 - 2.11

Yes

0.100 to 0.192

Zircon

1.810 - 1.984

Yes

0.001 to 0.059

Spessartite Garnet

1.79 - 1.82

None

NA

Almandine Garnet

1.77 - 1.82

None

NA

Star Ruby

1.762 - 1.778

Yes

0.008

Ruby

1.762 - 1.778

Yes

0.008

Star Sapphire

1.762 - 1.778

Yes

0.008

Color-change Sapphire

1.762 - 1.778

Yes

0.008

Sapphire

1.762 - 1.778

Yes

0.008

Alexandrite

1.746 - 1.763

Yes

0.004 to 0.010

Chrysoberyl Cat's Eye

1.746 - 1.763

Yes

0.004 to 0.010

Chrysoberyl

1.746 - 1.763

Yes

0.007 to 0.011

Grossularite Garnet

1.734 - 1.759

None

NA

Tsavorite Garnet

1.734 - 1.759

None

NA

Mali Garnet

1.734 - 1.759

None

NA

Hessonite Garnet

1.73 - 1.75

None

NA

Color-Change Garnet

1.73 - 1.756

None

NA

Star Garnet

1.72 - 1.756

None

NA

Pyrope Garnet

1.72 - 1.756

None

NA

Rhodolite Garnet

1.72 - 1.76

None

NA

Azurite

1.72 - 1.848

Yes

0.108 to 0.110

Rhodonite

1.716 - 1.752

Yes

0.010 to 0.014

Spinel

1.712 - 1.762

None

NA

Kyanite

1.71 - 1.734

Yes

0.0015 to 0.033

Color-Change Diaspore

1.702 - 1.75

Yes

0.048

Cat's Eye Diaspore

1.702 - 1.75

Yes

0.048

Idocrase

1.7 - 1.723

Yes

0.002 to 0.012

Ruby-Zoisite

1.691 - 1.7

Yes

0.009

Tanzanite

1.691 - 1.7

Yes

0.009

Dumortierite Quartz

1.678 - 1.689

Yes

0.015 to 0.037

Tashmarine Diopside

1.664 - 1.73

Yes

0.024 to 0.031

Star Diopside

1.664 - 1.73

Yes

0.024 to 0.031

Chrome Diopside

1.664 - 1.73

Yes

0.024 to 0.031

Kunzite

1.66 - 1.681

Yes

0.014 to 0.016

Hiddenite

1.66 - 1.681

Yes

0.014 to 0.016

Spodumene

1.66 - 1.681

Yes

0.014 to 0.016

Axinite

1.656 - 1.704

Yes

0.010 to 0.012

Sillimanite Cat's Eye

1.655 - 1.684

Yes

0.014 to 0.021

Malachite

1.655 - 1.909

Yes

0.254

Peridot

1.65 - 1.703

Yes

0.036 to 0.038

Danburite

1.63 - 1.636

Yes

0.006 to 0.008

Clinohumite

1.629 - 1.674

Yes

0.029 - 0.045

Apatite

1.628 - 1.649

Yes

0.002 to 0.006

Cat's Eye Apatite

1.628 - 1.649

Yes

0.002 to 0.006

Andalusite

1.627 - 1.649

Yes

0.007 to 0.013

Smithsonite

1.621 - 1.849

Yes

0.228

Paraiba Tourmaline

1.614 - 1.666

Yes

0.014 to 0.032

Cat's Eye Tourmaline

1.614 - 1.666

Yes

0.014 to 0.032

Tourmaline

1.614 - 1.666

Yes

0.014 to 0.032

Rubellite Tourmaline

1.614 - 1.666

Yes

0.014 to 0.032

Chrome Tourmaline

1.614 - 1.666

Yes

0.014 to 0.032

Hemimorphite

1.614 - 1.636

Yes

0.022

Prehnite

1.611 - 1.669

Yes

0.0021 to 0.039

Turquoise

1.61 - 1.65

Yes

0.04

Gaspeite

1.61 - 1.81

Yes

0.22

Imperial Topaz

1.609 - 1.643

Yes

0.008 to 0.016

Mystic Topaz

1.609 - 1.643

Yes

0.008 to 0.016

Rutile Topaz

1.609 - 1.643

Yes

0.008 to 0.016

Topaz

1.609 - 1.643

Yes

0.008 to 0.016

Azotic Topaz

1.609 - 1.643

Yes

0.008 to 0.016

Sugilite

1.607 - 1.611

Yes

0.001 to 0.004

Jadeite

1.6 - 1.627

Yes

0.027

Nephrite Jade

1.6 - 1.627

Yes

0.027

Rhodochrosite

1.6 - 1.82

Yes

0.208 to 0.220

Larimar

1.595 - 1.645

Yes

0.038

Howlite

1.586 - 1.605

Yes

0.019

Seraphinite

1.576 - 1.599

Yes

0,005 to 0.011

Emerald

1.565 - 1.602

Yes

0.006

Cat's Eye Aquamarine

1.564 - 1.596

Yes

0.004 to 0.005

Aquamarine

1.564 - 1.596

Yes

0.004 to 0.005

Variscite

1.563 - 1.594

Yes

0.031

Goshenite

1.562 - 1.602

Yes

0.004 to 0.010

Morganite

1.562 - 1.602

Yes

0.004 to 0.010

Beryl

1.562 - 1.602

Yes

0.004 to 0.010

Serpentine

1.56 - 1.571

Yes

0.008 to 0.014

Labradorite

1.559 - 1.57

Yes

 0.008 to 0.010 

Hambergite

1.553 - 1.628

Yes

0.0072

Verdite

1.552 - 1.576

None

NA

Andesine Labradorite

1.551 - 1.56

Yes

0.0008

Charoite

1.55 - 1.561

Yes

0.004 to 0.009

Mystic Quartz

1.544 - 1.553

Yes

0.009

Ametrine

1.544 - 1.553

Yes

0.009

Aventurine

1.544 - 1.553

Yes

0.009

Rose Quartz

1.544 - 1.553

Yes

0.009

Smoky Quartz

1.544 - 1.553

Yes

0.009

Pietersite

1.544 - 1.553

Yes

0.009

Strawberry Quartz

1.544 - 1.553

Yes

0.009

Quartz

1.544 - 1.553

Yes

0.009

Citrine

1.544 - 1.553

Yes

0.009

Amethyst

1.544 - 1.553

Yes

0.009

Rutile Quartz

1.544 - 1.553

Yes

0.009

Onyx

1.544 - 1.553

Yes

up to 0.004

Iolite

1.542 - 1.578

Yes

Jasper

1.54

None

NA

Peanut Wood

1.54

None

NA

Cat's Eye Scapolite

1.54 - 1.579

Yes

0.006 to 0.037

Scapolite

1.54 - 1.579

Yes

0.006 to 0.037

Amber

1.539 - 1.545

None

NA

Tiger's Eye

1.534 - 1.54

None

NA

Quartz Cat's Eye

1.534 - 1.54

None

NA

Tiger's Eye Matrix

1.534 - 1.54

None

NA

Bloodstone

1.53 - 1.54

Yes

up to 0.004

Dendritic Agate

1.53 - 1.54

Yes

up to 0.004

Agate Geode

1.53 - 1.54

Yes

up to 0.004

Star Rose Quartz

1.53 - 1.54

Yes

0.009

Agate

1.53 - 1.54

Yes

up to 0.004

Chalcedony

1.53 - 1.54

Yes

up to 0.004

Fossil Coral

1.53 - 1.54

Yes

up to 0.004

Fire Agate

1.53 - 1.54

Yes

up to 0.004

Chrysoprase

1.53 - 1.54

Yes

0.004 to 0.009

Carnelian

1.53 - 1.54

Yes

up to 0.004

Sunstone

1.525 - 1.548

Yes

0.01

Star Sunstone

1.525 - 1.548

Yes

0.01

Lepidolite

1.525 - 1.586

Yes

0.0290 to 0.0380

Amazonite

1.522 - 1.53

Yes

0.008

Maw-Sit-Sit

1.52 - 1.74

Yes

0.0150 to 0.020

Pearl

1.52 - 1.69

Yes

0.156

Ammolite

1.52 - 1.68

Yes

0.155

Rainbow Moonstone

1.518 - 1.526

Yes

0.008

Star Moonstone

1.518 - 1.526

Yes

0.008

Orthoclase

1.518 - 1.53

Yes

0.008

Moonstone

1.518 - 1.526

Yes

0.008

Lapis Lazuli

1.5

None

NA

Coral

1.486 - 1.658

Yes

White and red: 
0.160 to 0.172

Calcite

1.486 - 1.658

Yes

0.172

Sodalite

1.48

None

NA

Hackmanite

1.48

None

NA

Moldavite

1.48 - 1.54

None

NA

Chrysocolla

1.469 - 1.57

Yes

0.023 to 0.040

Obsidian

1.45 - 1.55

None

NA

Snowflake Obsidian

1.45 - 1.55

None

NA

Fluorite

1.434

None

NA

Boulder Opal

1.37 - 1.52

None

NA

Opal Doublet

1.37 - 1.52

None

NA

Opal

1.37 - 1.52

None

NA

Fire Opal

1.37 - 1.52

None

NA

Moss Opal

1.37 - 1.52

None

NA