Minerals T - Z

Minerals T - Z

Tanzanite 
Location: Tanzania, Africa
Variety of: Zoisite 
Chemical Composition: Ca2Al3(SiO4)3(OH), Calcium Aluminum Silicate Hydroxide
Hardness: 6.5 - 7

 

Tigereye
This is a combination of raw and tumbled tigereye. In the tumbled stones, there are yellow, blue, and red tigereye.
Variety of: Quartz
Chemical Composition: NaFe(SiO3)2 Sodium and iron with silicon dioxide (quartz)
Hardness: 6.5 - 7
 

 

Black Tourmaline
Alternate October Birthstone
General composition: (Na, Ca)(Li, Mg, Al)(Al, Fe, Mn)6(BO3)3(Si6O18)(OH)4 
Hardness: 7.0 - 7.5

 

Black Tourmaline on quartz
Alternate October Birthstone
General composition: (Na, Ca)(Li, Mg, Al)(Al, Fe, Mn)6(BO3)3(Si6O18)(OH)4 
Quartz is: SiO2
Hardness: 7.0 - 7.5

 

Tourmaline with quartz 
Alternate October Birthstone
Location: Brazil 
General composition: (Na, Ca)(Li, Mg, Al)(Al, Fe, Mn)6(BO3)3(Si6O18)(OH)4 
Quartz is: SiO2
Hardness: 7.0 - 7.5

 

Tourmaline Rubellite
Alternate October Birthstone
Location: Kunar, Afghanistan
General composition: (Na, Ca)(Li, Mg, Al)(Al, Fe, Mn)6(BO3)3(Si6O18)(OH)4 
Hardness: 7.0 - 7.5

 

Turquoise
Location: Arizona
Chemical Composition: CuAl6(PO4)4(OH)8*5(H2O), Hydrated Copper Aluminum Phosphate
Hardness: 5 - 6

 

Utah Picture Stone

Variety of sandstone
Chemical composition: SiO2 with varying amounts of iron oxides.
Location: St. George, Utah
Period: Triassic, estimated as being 150 million years old.
 
 
 
 
Uvarovite 
Green Garnet
Location: Utal Mts., Russia
Vitreous, resinous green.
Chemical Composition: Ca3Cr2(SiO4)3, Calcium Chromium Silicate
Hardness is 6.5 - 7
 
 
 
 
Vanadinite
Location: Mibladen Mine
Morocco
Sub-resinous/sub-adamantine orange, red, brown, yellow, etc.
Chemical Composition: Pb5(VO4)3Cl , Lead Chlorovanadate
Hardness: 3
 
 
 

Vivianite 
Location: Ukraine
Chemical Composition: Fe3(PO4)2-(H2O)8, Hydrated Iron Phosphate
Hardness: 1.5 - 2

 

Wavellite 
Location: Arkansas
Chemical Composition: Al3(PO4)2(OH)3-(H2O)5, Hydrated Aluminum Phosphate Hydroxide
Hardness: 3.5 - 4

 

Wulfenite 
Location: Red Cloud Mine, Arizona
Chemical Composition: PbMoO4, Lead Molybdate
Hardness: 3

 

Zircon crystal 
December Birthstone
Location: Kunar, Afghanistan
Chemical Composition: ZrSiO4, Zirconium Silicate
Hardness: 7.5