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Gem Resources International
Gem Resources
PO Box 62006
Minneapolis, MN 55426


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Gemstone Properties

Name Structure Hardness Specific Gravity Refractive index Doubly Refracting
(bi-refraction)
Abalone2.51.3none
Achroite (Tourmaline)7.53.061.62 - 1.60.018
Agate ( Chalcedony)72.611.53 - 1.50.004
Alexandrite8.53.731.741 - 1.
Almandine ( Garnet )7.541.76 - 1.8None
Amber2.51.081.54 - 1.5Not Availa
Amethyst ( Quartz)72.651.54 - 1.50.009
AmmoliteOrthorhombic42.81.52 - 1.6
Andalusite7.53.161.63 - 1.60.01
Andradite Garnet6.53.851.85 - 1.8None
Apatite53.21.63- 1.640.003
Aquamarine ( Beryl )7.52.691.57 - 1.50.006
Aventurine ( Quartz )72.651.54 - 1.50.009
AzuriteMonoclinic3.53.771.73 - 1.80.11
BenitoiteHexagonal6.53.671.76 - 1.80.047
Bloodstone ( Chalcedony )72.611.53 - 1.50.004
Brown Quartz ( Smokey Quartz )72.651.54 - 1.50.009
Calcite32.711.48 - 1.60.172
Carnelian ( Chalcedony )72.611.53 - 1.50.004
Cassiterite6.56.952.00 - 2.10.1
Celestine3.53.981.62 - 1.60.01
Cerussite3.56.511.80 - 2.00.274
Chalcedony72.611.53 - 1.50.004
Chatoyant Quartz72.651.54 - 1.50.009
Chrysoberyl8.53.711.74 - 1.70.009
Chrysocolla22.21.57 - 1.60.03
Chrysoprase (Chalcedony)72.611.53 - 1.50.004
Citrine ( Quartz )72.651.54 - 1.50.009
Coral32.681.49 - 1.6Not Availa
Danburite731.63 - 1.60.006
DiamondCubic103.522.42None
Diopside5.53.291.66 - 1.70.029
Dioptase53.311.67 - 1.70.053
Dravite ( Tourmaline)7.53.061.61 - 1.60.018
Emerald ( Beryl )7.52.711.57 - 1.50.006
Enstatite5.53.271.66 - 1.60.01
Epidote6.53.41.74 - 1.70.035
EuclaseMonoclinic7.53.09 - 3.11.65 - 1.60.019
Fire Agate (Chalcedony)Trigonal72.611.53 - 1.50.004
FluoriteCubic43.181.43None
GoldCubic2.519.3NoneNone
Goshenite (Beryl)Hexagonal7.52.81.58 - 1.50.008
Grossular Garnet (Tsavorite Garnet)Cubic73.491.69 - 1.7none
GypsumMonoclinic22.321.52 - 1.50.01
Heliodor ( Beryl )Hexagonal7.52.81.57 - 1.50.005
HematiteTrigonal6.55.22.94 - 3.20.28
Hessonite (Grossular Garnet)Cubic7.253.651.73 - 1.7none
Imperial Topaz
Indicolite ( Tourmaline)Trigonal7.53.061.62 - 1.60.018
IoliteOrthorhombic72.631.53 - 1.50.01
IvoryAmorphous2.51.91.53 - 1.5not availa
JadeiteMonoclinic73.331.66 - 1.60.012
Jasper (Chalcedony)Trigonal72.611.53 - 1.50.004
JetAmorphous2.51.331.64 - 1.6not availb
KornerupineOrthorhombic6.53.321.66 - 1.60.013
KunziteMonoclinic73.181.66 - 1.60.015
KyaniteTriclinic5 or3.681.71 - 1.70.017
LabradoriteTriclinic62.71.56 - 1.50.01
Lapis Lazuli ( Lazurite)various5.52.81.5none
LazuliteMonoclinic5.53.11.61 - 1.60.031
MalachiteMonoclinic43.81.850.025
MeerschaumMonoclinic2.51.51.51 - 1.5none
MicroclineTriclinic62.561.52 - 1.50.008
Milky QuartzTrigonal72.651.54 - 1.50.009
MoonstoneMonoclinic62.571.52 - 1.50.005
Morganite ( Beryl)Hexagonal7.52.81.58 - 1.50.008
Nephrite ( Jade)Monoclinic6.52.961.61 - 1.60.027
ObsidianAmorphous52.351.48 - 1.5none
OligoclaseTriclinic62.641.54 - 1.50.007
OnyxTrigonal72.611.53 - 1.50.004
OpalAmorphous62.11.37 - 1.4none
OrthoclaseMonoclinic62.561.51 - 1.50.005
Padparasha ( Corundum)Trigonal941.76 - 1.70.008
PearlOrthorhombic32.711.53 - 1.6not availb
PeridotOrthorhombic6.53.341.64 - 1.60.036
Pink Topaz ( Mercury Myst Vapor )
Plasma ( Chalcedony)Trigonal72.611.53 - 1.50.004
Prase ( Chalcedony )Trigonal72.611.53 - 1.50.004
PrehniteOrthorhombic62.871.61 - 1.60.016
PyriteCubic64.9nonenone
Pyrope ( Garnet )Cubic7.253.81.72 - 1.7none
Rock Crystal ( Quartz )Trigonal72.651.54 - 1.50.009
Rubellite ( Tourmaline)Trigonal7.53.061.62 - 1.60.018
Ruby ( Corundum)Trigonal941.76 - 1.70.008
Sapphire ( Corundum)Trigonal941.76 - 1.70.008
Sardonyx ( Chalcedony)Trigonal72.611.53 - 1.50.004
ScapoliteTetragonal62.71.54 - 1.50.02
Schorl (Tourmaline)Trigonal7.53.061.62 - 1.60.018
ShellVarious2.51.31.53 - 1.5not availa
Spessarite (Garnet)Cubic74.161.79 - 1.8none
SphaleriteCubic3.54.092.36 - 2.3none
Spinelcubic83.61.71 - 1.7none
Spodumene (Hiddenite - Triphane)Monoclinic73.181.66 - 1.60.015
Tanzanite (Zoisite)Orthorhombic6.53.351.69 - 1.70.01
Tektites ( Moldavite )Currently Out of Stock52.41.48 - 1.5none
Tiger Eye
Titanite (Sphene)Monoclinic53.531.84 - 2.00.12
TopazOrthorhombic83.541.62 - 1.60.01
TurquoiseTriclinic62.81.61 - 1.60.04
YAG (Garnet)Isometric8.54.551.833
ZirconTetragonal7.54.691.93 - 1.90.059
 
 
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