Mineral Name..................RI...Deviation or DR

Assembled stone........any

Plastic................1.46-1.70

Fluorite...............1.434....none

Glass..................1.44-1.90

Opal...................1.45....none

Sodalite...............1.483....none

Natrolite..............1.48-1.493

Obsidian...............1.48-1.51

Calcite................1.486-1.658

Tugtupite..............1.496-1.50

Coral..................1.486-1.658

Calcite................1.486-1.658

Hauynite...............1.502....none

Moldavite..............1.50....none

Lapis..gem.............1.50....none

Chrysocolla............1.50....none

Obsidian...............1.50....none

Leucite................1.5085....none

Petalite...............1.502-1.52

Ulexite................1.49-1.52

Cancrinite.............1.491-1.524

Gaylussite.............1.517....none

Sanidine...............1.522....none

Orthoclase..feldspar...1.525... .005

Amazonite..feldspar....1.525.... .005

Microcline..feldspar...1.525.... .005

Albite..feldspar.......1.525-1.536

Adularia..moonstone....1.525.... .005

Meerschaum.............1.53....none

Peristerite............1.525-1.536

Apophyllite............1.536....none

Chrysoprase............1.534.... .005

Chalcedony.............1.53-1.539

Thomsonite.............1.53.... .01

Adventurine..feldspar..1.532-1.542

Elaeolite..............1.532-1.549

Stichtite..............1.52 -1.55

Jasper.................1.54....none

Albite..moonstone......1.535.... .005

Amber..................1.54....none

Cordierite.............1.54.... .01

Moss agate.............1.54-1.55

Agalmatoite............1.55....none

Iolite.................1.548.....010

Oligoclase..feldspar...1.539-1.547

Ivory..................1.54....none

Tiger eye..............1.544-1.553

Prasiolite.............1.54-1.553

Prase..................1.54-1.533

Serpentine.............1.555.... .005

Quartz.................1.55.... .009

Citrine................1.55.... .009

Rock crystal...........1.544-1.553

Adventurine.quartz.....1.544-1.533

Amethyst...............1.544-1.553

Agate..................1.544-1.553

Scapolite..............1.54-1.56

Beryllonite............1.553-1.562

Scapolite (yellow).....1.555.... .020

Serpentine.............1.56-1.57

Labradorite..feldspar..1.565.... .005

Serpentine.............1.56-1.571

Brownite...............1.567-1.576

Beryl..................1.577-1.60

Emerald................1.576-1.582

Aquamarine.............1.577-1.583

Shell..................1.53-1.686

Synth Emerald..flux....1.561-1.564

Synth Emerald..hydro...1.568-1.573

Augelite...............1.574-1.588

Steatite...............1.539-1.589

Variscite..............1.55-1.59

Wardite................1.59-1.599

Ekanite................1.60....none

Howlite................1.586-1.609

Anhydrite..............1.571-1.614

Colemanite.............1.586-1.614

Tremolite..............1.60-1.62

Brazilianite...........1.603-1.623

Vivianite..............1.580-1.627

Nephrite..jade.........1.600-1.627

Smaragdite.............1.608-1.63

Hambergite.............1.559-1.631

Celestite..............1.622-1.631

Hemimorphite...........1.614-1.636

Turquoise..gem.........1.61....none

Nephrite..jade.........1.61....none

Tourmaline.............1.63.... .01

Andalusite.............1.635.... .005

Topaz (white)..........1.63.... .008

Topaz (blue)...........1.61.... .01

Topaz (pink,yellow)....1.62.... .01

Tourmaline.............1.63.... .018

Danburite..............1.633.... .006

Amblygonite............1.611-1.637

Andalusite.............1.64.... .010

Apatite................1.63-1.640

Coral..................1.486-1.658

Pearl..................1.53-1.686

Jadeite................1.665.... .005

Nephrite...............1.60-1.63

Turquoise..............1.61-1.65

Prehnite...............1.61-1.64

Actinolite.............1.618-1.641

Lazulite...............1.615-1.645

Apatite................1.632-1.648

Topaz..................1.62-1.627

Tourmaline.............1.624-1.644

Andalusite.............1.634-1.643

Barite.................1.636-1.648

Andalusite.............1.641-1.648

Tourmaline.............1.616-1.652

Onyx...................1.486-1.658

Phenakite..............1.65-1.67

Euclase................1.652-1.672

Fibrolite..............1.659-1.680

Sillimanite............1.658-1.678

Witherite..............1.532-1.68

Enstatite..............1.663-1.673

Spodumene..............1.65-1.68

Peridot................1.65-1.69

Jet....................1.66....none

Kunzite................1.655-1.68

Hiddenite..............1.655-1.68

Dolomite...............1.503-1.682

Kornerupine............1.665-1.682

Barytocalcite..........1.684

Aragonite..............1.530-1.685

Axinite................1.675-1.685

Pearl..................1.52-1.69

Malachite..............1.66-1.91

Jadeite................1.66-1.68

Peridot................1.654-1.69

Olivine................1.67.... .02

Rhodizite..............1.69

Zoisite................1.695.... .005

Tanzanite..............1.691-1.70

Sinhalite..............1.699-1.707

Diopside...............1.68-1.71

Magnesite..............1.515-1.717

Willemite..............1.69-1.72

Idocrase...............1.713-1.72

Taaffeite..............1.72

Dumortierite...........1.686-1.723

Hypersthene............1.67-1.73

Kyanite................1.715-1.732

Clinozoisite...........1.724-1.734

Spinel.................1.712-1.736

Synthetic Spinel.......1.73

Rhodonite..............1.735.... .005

Grossular..garnet......1.74

Periclase..............1.74

Rhodonite..............1.73-1.74

Grossular..garnet......1.738-1.745

Hessonite..garnet......1.745

Chrysoberyl............1.745.... .005

Alexandrite............1.745-1.759

Pyrope.................1.74.... .015

Rhodolite..garnet......1.76

Andradite..garnet......1.82-1.89

Staurolite.............1.739-1.762

Epidote................1.733-1.768

Corundum...............1.766-1.774

Ruby...................1.76-1.77

Sapphire...............1.76-1.77

Ceylanite..............1.77-1.80

Almandite..garnet......1.79

Benitoite..............1.757-1.8

Pyrite.................1.81 and over

Zircon..low............1.80.... .01

Rhodochrisite..........1.60-1.82

Spessartite..garnet....1.81

Painite................1.787-1.816

Almandine..garnet......1.76-1.83

YAG....................1.83

Azurite................1.73-1.838

Smithsonite............1.621-1.849

Chalybite..............1.63-1.87

Uvarovite..............1.87

Demantoid..garnet......1.88

Malachite..............1.66-1.91

Malachite..............1.655-1.909

Purpurite..............1.84-1.92

Scheelite..............1.92-1.934

Zircon...high..........1.96-2.01

Zincite................2.01-1.03

Sphene.................1.885-2.05

Cerussite..............1.804-2.078

Cassiterite............1.997-2.093

Chromite...............2.1

Phosgenite.............2.117-2.145

Sulphur................1.96-2.248

Sphalerite.............2.368-2.371

Wulfenite..............2.300-2.40

Tantalite..............2.24-2.41

GGG....................2.02

Cubic Zirconia.........2.17

Strontium Titanate.....2.41

Diamond................2.417-2.419

Anatase................2.49-2.55

Crocoite...............2.31-2.66

Cuprite................2.85

Rutile.................2.61-2.90

Proustite..............2.79-3.088

Hematite...............2.94-3.22