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Alphabetical Gemstone List
Click on a letter for a list of gems:

A| B| C| D| E| F| G| H| I| J| K| L| M| N| O| P| Q| R| S| T|U| V| W| X|Y |Z

Gemstones that begin with the letter "T"

Gemstone Crystal System Density Hardness Refractive index Treatments

taaffeite
Taaffeite

hexagonal 3.61 8.0-8.5 1.719-.732 none known

thompsonite
Thomsonite

aggregate 2.35 5.0-5.5 1.515-1.540 none known

tanzanite
Tanzanite

orthorhombic 3.30 6.0-7.0 1.690-1.700 heat

tigereye
Tiger-eye

microcrystalline 2.64-2.71 7.0 1.540-1.550 bleaching w/
honey tigereye

topaz
Topaz

orthorhombic 3.53 8.0 1.619-1.627 blue is irradiated

tourmaline
Tourmaline

trigonal 3.06 7.0-7.5 1.624-1.644 (green) heat
tsavorite
Tsavorite
cubic 3.84 6.5 - 7 1.73 - 1.75 none
tugtupite
Tugtupite
aggregate 2.36 4.0-6.5 1.496-1.502 none

turquoise
Turquoise

triclinic 2.73 5.0-6.0 1.610-1.650 dying, sealing