Hackmanite

Big Photo

Badakhshan, Afghanistan
0.35 carats
© Rarestone.com

Hackmanite is a pink, pale to deep violet variety of Sodalite, but the colour fades quickly to greyish or greenish white in sunlight (so-called tenebrescence). Some hackmanites (from Afghanistan and Burma) start off creamy white but develop a violet to pink-red colour in sunlight, which can fade again if left in a dark environment for some time.

It was first discovered in cuttable qualities in 1991, in Quebec, Canada.

Hackmanite Gemstones by Colour

This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
 
 

Hackmanite Gemstones by Size

This table shows distribution of Hackmanite gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:0.19 cts
Heaviest:8.44 cts
Average:1.51 cts
Total photos:27
Do you have a larger Hackmanite? Why not upload a photo?
0.19ct to 1.02ct1.02ct to 1.84ct1.84ct to 2.67ct2.67ct to 3.49ct3.49ct to 4.32ct4.32ct to 5.14ct5.14ct to 5.97ct5.97ct to 6.79ct6.79ct to 7.62ct7.62ct to 8.44ct
General Information
A variety or type of:Sodalite
Chemical Formula
Na
 
8
Al
 
6
Si
 
6
O
 
24
Cl
 
2
Michael O’Donoghue, Gems, Sixth Edition (2006)
Photos of natural/un-cut material from mindat.org
Physical Properties of Hackmanite
Mohs Hardness5.5 to 6
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Specific Gravity2.27 to 2.33
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
TenacityBrittle
Anthony et al, Handbook of mineralogy (2001)
Cleavage QualityPoor
Arthur Thomas, Gemstones (2009)
FractureUneven
Arthur Thomas, Gemstones (2009)
Light SensitivityColour fades in light.
Walter Schumann, Gemstones of the world (2001)
Optical Properties of Hackmanite
Refractive Index1.483 to 1.487
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Optical CharacterIsotropic
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Colour
Colour (General)Pink
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
TransparencyTransparent
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
LustreVitreous,Greasy
Arthur Thomas, Gemstones (2009)
Fluorescence & other light emissions
Fluorescence (General)Pink to violet-red when exposed to UV, fades to yellow in visible light
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Crystallography of Hackmanite
Crystal SystemIsometric
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Further Information
Mineral information:Hackmanite information at mindat.org
Significant Gem Localities
Myanmar
 
  • Mandalay Region
    • Pyin-Oo-Lwin District
        • Marble Ark
Ted Themelis (2008) Gems & mines of Mogok
        • Mogok Valley
          • Dattaw-taung (Dattaw hill)
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
        • Pein-Pyit (Painpyit; Pyan Pyit)
Ted Themelis (2008) Gems & mines of Mogok
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