Tanzanite (Zoisite) Gemstones

  • Hardness

    6.5 on the Mohs scale.

  • Occurrence

    Zoisite occurs in Tanzania (tanzanite) and Kenya, Norway, Austria, Western Australia, Italy, USA (North Carolina)

  • Appearance

    Tanzanite, colored by Vanadium, is normally heat treated to bring out the intense purple, blue and greyish colors. The color seen depends on the angle they are viewed from. Under incandescent lighting, they can appear more violet. Can be confused with iolite. Tanzanite is also produced synthetically, and a new treatment of beryl produces a dark blue beryl that is very similar in color to tanzanite.

  • Enhancements

    Tanzanite is usually heat treated to produce violet-blue color.

    More information on gemstone enhancements.

  • Gemstone Family

    Tanzanite is a member of the Zoisite gemstone family.

  • Heat Treatment

    Violet-Blue Tanzanite is the result of heat-treatment, as the following photo illustrates:

    Rough Zoisite

Tanzanite
Tanzanite

TNZ190
TNZ190
0.40 ct. total, 'A' Grade
2.8mm Round Cut
Light
Moderately Strong Violetish Blue
Very Slightly Included
[H] Heated to improve color.
Only one pair available.
Tanzanite

TNZ192
TNZ192
0.24 ct. total, 'A' Grade
3.0mm Round Cut
Light
Strong Bluish Violet
Loupe Clean
[H] Heated to improve color.
Only one pair available.
Tanzanite

TNZ195
TNZ195
0.33 ct., 'A' Grade
4.0mm Round Cut
Light
Strong Bluish Violet
Loupe Clean
[H] Heated to improve color.
Quantity Available: 2
Tanzanite

TNZ206
TNZ206
0.34 ct., 'AAA' Grade
4.3mm Round Cut
Medium
Moderately Strong Bluish Purple
Loupe Clean
[H] Heated to improve color.
One of a kind.
Tanzanite

TNZ111
TNZ111
4.11 ct.
14.0x7.9mm Pear Cut
Medium Dark
Strong Bluish Violet
Flawless
[E] Routinely enhanced.
One of a kind.
Tanzanite

TNZ181
TNZ181
1.80 ct.
9.0x6.7mm Pear Cut
Medium
Vivid Violet
Loupe Clean
[E] Routinely enhanced.
One of a kind.
With Greenish Yellow.
Bi-Color

TNZ106
TNZ106
0.39 ct.
6.9x3.0mm Marquise Cut
Medium
Strong Violetish Blue
Slightly Included
[E] Routinely enhanced.
One of a kind.
Tanzanite

Calibrated Tanzanite
Calibrated Tanzanite

Specify size, shape and quality when ordering. Prices are subject to change without notice. Actual carat weight may vary from the average carat weight listed.

  • AAA Clean, medium dark bluish purple, brilliant, excellent cut and polish, no color zoning.
  • AA Clean, medium dark, bluish purple, good cut, good polish, good brilliance, little or no color zoning.
  • A Clean, medium light, bluish purple, good cut, good polish, good brilliance, little or no color zoning.
  • B Clean, light, bluish purple, good cut, good polish, good brilliance, little color zoning.

Tanzanite Quality AAA AA A B
Shape Size Avg. Weight Price Each
1.75mm
0.03 ct.
   
2mm
0.04 ct.
   
2.25mm
0.06 ct.
   
2.5mm
0.08 ct.
   
2.75mm
0.10 ct.
   
3mm
0.12 ct.
   
3.5mm
0.19 ct.
   
4mm
0.27 ct.
 
4.5mm
0.42 ct.
 
5mm
0.55 ct.
 
5.5mm
0.70 ct.
 
6mm
0.88 ct.
 
6.5mm
1.15 ct.
  
7mm
1.40 ct.
    
 
  AAA AA A B
4x3mm
0.20 ct.
 
5x3mm
0.25 ct.
 
5x4mm
0.37 ct.
 
6x4mm
0.50 ct.
 
7x5mm
0.85 ct.
 
8x6mm
1.35 ct.
 
 
  AAA AA A B
4x3mm
0.16 ct.
   
5x3mm
0.23 ct.
   
6x4mm
0.45 ct.
   
7x5mm
~
   
8x6mm
~
    
9x6mm
~
    
10x7mm
~
    
 
  AAA AA A B
4x2mm
0.09 ct.
 
5x2.5mm
0.15 ct.
 
6x3mm
0.25 ct.
 
7x3.5mm
0.38 ct.
 
8x4mm
0.60 ct.
 
9x4.5mm
0.85 ct.
 
10x5mm
1.15 ct.
  
 
  AAA AA A B
4x3mm
0.20 ct.
5x3mm
0.27 ct.
6x4mm
0.60 ct.
 
7x5mm
1.00 ct.
 
8x6mm
1.70 ct.
 
 
  AAA AA A B
3mm
0.10 ct.
   
3.5mm
0.16 ct.
 
4mm
0.23 ct.
4.5mm
0.31 ct.
5mm
0.45 ct.
5.5mm
0.55 ct.
 
6mm
0.75 ct.
 
6.5mm
0.88 ct.
 
 
  AAA AA A B
4x2mm
0.13 ct.
   
5x2mm
0.17 ct.
    
 
  AAA AA A B
2mm
0.06 ct.
 
2.25mm
0.07 ct.
 
2.5mm
0.09 ct.
 
2.75mm
0.11 ct.
 
3mm
0.15 ct.
 
3.5mm
0.24 ct.
 
4mm
0.35 ct.
 
4.5mm
0.45 ct.
 
5mm
0.58 ct.
 
5.5mm
0.85 ct.
 
6mm
1.10 ct.
   
 
  AAA AA A B
4mm
~
    
6mm
~
    
8mm
~
    
10mm
~