![emerald cut amethyst from Madagascar](https://www.patrickvoillot.com/wp-content/uploads/2021/03/amethyste-violette-madagascar-taille-emeraude257-150x150.png)
![sturmanite emerald cut](https://www.patrickvoillot.com/wp-content/uploads/2021/03/sturmanite-taille-emeraude52-300x202.png)
sturmanite
Detailed sheet
sturmanite
It honors the name of the Canadian mineralogist B. Darko Sturman.
![](https://www.patrickvoillot.com/wp-content/uploads/2021/04/zoom-in.png)
![](https://www.patrickvoillot.com/wp-content/themes/astra-child/images/icon-image.png)
CHEMICAL CHARACTERISTICS
Ca6(Fe,Al,Mn)2[SO4]2 B(OH)4(OH)12 - 25(H2O)
complex sulfate
![](https://www.patrickvoillot.com/wp-content/uploads/2021/04/zoom-in.png)
![](https://www.patrickvoillot.com/wp-content/themes/astra-child/images/icon-image2.png)
PHYSICAL CHARACTERISTICS
Main color
yellow
Other colors
orange, green
Color of streak
yellow
Luster
greasy, vitreous
Hardness
2.5 to 0.0
Density
1.85 to 0.00
Cleavage
perfect
Fracture
uneven
![](https://www.patrickvoillot.com/wp-content/uploads/2021/04/zoom-in.png)
![](https://www.patrickvoillot.com/wp-content/themes/astra-child/images/icon-image3.png)
OPTICAL PROPERTIES
Transparency
translucent, transparent
Refractive index
1.500 - 1.505
Double refraction
0.005
very weak, uniaxial (+)
visible double refraction
No
Pleochroism
very weak
Number of colors
2
light green, yellow green
Fluorescence
none
![](https://www.patrickvoillot.com/wp-content/uploads/2021/04/zoom-in.png)
![](https://www.patrickvoillot.com/wp-content/themes/astra-child/images/icon-image4.png)
CRYSTALS PROPERTIES
pseudo-hexagonal biterminals
![](https://www.patrickvoillot.com/wp-content/uploads/2021/03/cristal-sturmanite.gif)
crystals system
trigonal
![](https://www.patrickvoillot.com/wp-content/uploads/2021/04/zoom-in.png)
![](https://www.patrickvoillot.com/wp-content/themes/astra-child/images/icon-image5.png)
OTHER INFORMATIONS
![](https://www.patrickvoillot.com/wp-content/uploads/2021/04/zoom-in.png)
![](https://www.patrickvoillot.com/wp-content/themes/astra-child/images/icon-image6.png)
APPROACHING GEMS
Exploited
sites
Rare mineral, it is found in the Kalahari in South Africa, and in Russia in the Caucasus.
use in jewelry
it is cut only for collection because it is very fragile
Venez visitez
notre site web
voillot-joaillier.fr
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