Gemstone Properties

Name Structure Hardness Specific Gravity Refractive index Doubly Refracting
(bi-refraction)
Achroite TourmalineTrigonal7.53.061.62 - 1.60.018
AgateTrigonal72.611.53 - 1.50.004
AlbiteTriclinic62.641.54 - 1.50.009
Almandine Garnet, Almandite GarnetCubic7.541.76 - 1.8None
AmberAmorphous2.51.081.54 - 1.5
AmethystTrigonal72.651.54 - 1.50.009
AndalusiteOrthorhombic7.53.161.63 - 1.60.01
Andradite GarnetCubic6.53.851.85 - 1.8None
ApatiteHexagonal53.21.63- 1.640.003
AquamarineHexagonal7.52.691.57 - 1.50.006
AragoniteOrthorhombic3.52.941.53 - 1.60.155
AventurineTrigonal72.651.54 - 1.50.009
AzuriteMonoclinic3.53.771.73 - 1.80.11
BenitoiteHexagonal6.53.671.76 - 1.80.047
BloodstoneTrigonal72.611.53 - 1.50.004
Blue Topaz
BrazilianiteMonoclinic5.52.991.60 - 1.60.021
Brown Quartz, Smokey QuartzTrigonal72.651.54 - 1.50.009
CarnelianTrigonal72.611.53 - 1.50.004
ChalcedonyTrigonal72.611.53 - 1.50.004
Chatoyant QuartzTrigonal72.651.54 - 1.50.009
Chrome DiopsideMonoclinic5.53.291.66 - 1.70.029
Chrome Tourmaline
ChrysoberylOrthorhombic8.53.711.74 - 1.70.009
ChrysopraseTrigonal72.611.53 - 1.50.004
CitrineTrigonal72.651.54 - 1.50.009
CoralTrigonal32.681.49 - 1.6Not Availa
Corundum ( Sapphire )Trigonal941.76 - 1.70.008
DanburiteOrthorhombic731.63 - 1.60.006
DatoliteMonoclinic52.951.62 - 1.60.044
DiamondCubic103.522.42None
DioptaseTrigonal53.311.67 - 1.70.053
Dravite TourmalineTrigonal7.53.061.61 - 1.60.018
DumortieriteOrthorhombic73.281.69 - 1.70.037
EkaniteTetragonal6.253.31.57
EmeraldHexagonal7.52.711.57 - 1.50.006
EnstatiteOrthorhombic5.53.271.66 - 1.60.01
EpidoteMonoclinic6.53.41.74 - 1.70.035
EuclaseMonoclinic7.53.09 - 3.11.65 - 1.60.019
Fire AgateTrigonal72.611.53 - 1.50.004
FluoriteCubic43.181.43None
GoldCubic2.519.3NoneNone
GosheniteHexagonal7.52.81.58 - 1.50.008
Green Tourmaline
Grossular GarnetCubic73.491.69 - 1.7none
HauyneCubic62.41.5none
HeliodorHexagonal7.52.81.57 - 1.50.005
HematiteTrigonal6.55.22.94 - 3.20.28
Hessonite GarnetCubic7.253.651.73 - 1.7none
HowliteMonoclinic3.52.581.58 - 1.50.022
HyperstheneOrthorhombic5.53.351.65 - 1.60.01
Imperial Topaz
Indicolite TourmalineTrigonal7.53.061.62 - 1.60.018
IoliteOrthorhombic72.631.53 - 1.50.01
IvoryAmorphous2.51.91.53 - 1.5not availa
JadeiteMonoclinic73.331.66 - 1.60.012
JasperTrigonal72.611.53 - 1.50.004
JetAmorphous2.51.331.64 - 1.6not availb
KornerupineOrthorhombic6.53.321.66 - 1.60.013
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
Liddicoatite
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
MorganiteHexagonal7.52.81.58 - 1.50.008
Nephrite ( jade)Monoclinic6.52.961.61 - 1.60.027
ObsidianAmorphous52.351.48 - 1.5none
OligoclaseTriclinic62.641.54 - 1.50.007
Paraiba Tourmaline, Copper Bearing Tourmaline
PetaliteMonoclinic62.421.50 - 1.50.014
PhenakiteTrigonal7.52.961.65 - 1.60.015
PlatinumCubic421.4nonenone
PrehniteOrthorhombic62.871.61 - 1.60.016
PyriteCubic64.9nonenone
Pyro Spessartite Garnet, Color Change Garnet
Pyrope GarnetCubic7.253.81.72 - 1.7none
RhodochrositeTrigonal43.61.60 - 1.80.22
RhodoniteTriclinic63.61.71 - 1.70.014
Rock CrystalTrigonal72.651.54 - 1.50.009
Rubellite Tourmaline. Rubelite TourmalineTrigonal7.53.061.62 - 1.60.018
RubyTrigonal941.76 - 1.70.008
RutileTetragonal64.252.62 - 2.90.287
SardTrigonal72.611.53 - 1.50.004
ScapoliteTetragonal62.71.54 - 1.50.02
ScheeliteTetragonal56.11.92 - 1.90.017
Schorl TourmalineTrigonal7.53.061.62 - 1.60.018
SerpentineMonoclinic52.61.55 - 1.50.001
ShellVarious2.51.31.53 - 1.5not availa
SillimaniteOrthorhombic7.53.251.66 - 1.60.019
SinhaliteOrthorhombic6.53.481.67 - 1.70.038
SmithsoniteTriagonal54.351.62 - 1.80.23
SodaliteCubic5.52.271.48none
Spessarite GarnetCubic74.161.79 - 1.8none
SphaleriteCubic3.54.092.36 - 2.3none
SpheneMonoclinic53.531.84 - 2.00.12
Spinelcubic83.61.71 - 1.7none
SpodumeneMonoclinic73.181.66 - 1.60.015
TanzaniteOrthorhombic6.53.351.69 - 1.70.01
TektitesAmorphous52.41.48 - 1.5none
TopazOrthorhombic83.541.62 - 1.60.01
Tsilisite Tourmaline
TurquiseTriclinic62.81.61 - 1.60.04
Uvarite GarnetCubic7.53.771.86 - 1.8none
Vesuvianite ( Idocrase )Tetragonal6.53.41.70 - 1.70.005
Watermelon TourmalineTrigonal7.53.061.62 - 1.60.018
White Topaz
ZirconTetragonal7.54.691.93 - 1.90.059