![prehnite crystals from India](https://www.patrickvoillot.com/wp-content/uploads/2021/03/prehnite-cristaux-inde89-150x150.png)
![cabochon of dumortierite from Africa](https://www.patrickvoillot.com/wp-content/uploads/2021/03/dumortierite-cabochon-afrique187-300x200.png)
dumortierite
![blue dumortierite crystals from Sahatany in Madagascar](https://www.patrickvoillot.com/wp-content/uploads/2021/03/dumortierite-cristaux-sahatany-madagascar-300x200.jpg)
blue dumortierite crystals from Sahatany in Madagascar
![detail of blue dumortierite crystals from Sahatany in Madagascar](https://www.patrickvoillot.com/wp-content/uploads/2021/03/dumortierite-cristaux-sahatany-madagascar-3-300x200.jpg)
detail of blue dumortierite crystals from Sahatany in Madagascar
![Dumortiérite from Myanmar](https://www.patrickvoillot.com/wp-content/uploads/2021/03/dumortierite-birmanie-myanmar-300x221.jpg)
Dumortiérite from Myanmar
![liquid like inclusions, healing fissures](https://www.patrickvoillot.com/wp-content/uploads/2021/03/inclusions-dumortierite-foncee-300x200.jpg)
liquid like inclusions, healing fissures
Detailed sheet
dumortierite
Its name honors Eugene Dumortier, a paleontologist from Lyon (France )(1802-1873).
It occurs most commonly as quartz inclusions, it is then called “blue aventurine”.
![](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
Al7(BO3)[SiO4]3O3
aluminum boro - silicate
![](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
blue
Other colors
brown, red, purple
Color of streak
white
Luster
greasy, vitreous
Hardness
7.0 to 8.5
Density
3.25 to 3.40
Cleavage
good
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
opaque, translucent, transparent
Refractive index
1.680 - 1.720
Double refraction
0.015
can only be seen on transparent rocks, negative biaxial
visible double refraction
No
Dispersion
-
Pleochroism
strong
Number of colors
3
black, brown - red, brown
Fluorescence
weak
blue to violet
![](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
rare, prismatic. Often in aggregates.
![](https://www.patrickvoillot.com/wp-content/uploads/2021/03/cristal-dumortierite.gif)
crystals system
orthorhombic
![](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
Astrological sign
Pisces, Sagittarius, Scorpio
![](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
It is found in France, at Beaunan in the Monts du Lyonnais, Brazil, Canada, United States (California, Nevada), India, Madagascar, Mozambique, Namibia, Sri Lanka.
use in jewelry
It is cut into cabochons or silky platelets, used to make charms, figurines.
Very few small stones are transparent and cut in facets.
Historical
healing properties
It would be a brain stone, it would help formalize the concepts, thinking, logical thinking. Structuring stone it allows the mind to organize and reduce the excess of anger, spontaneous and uncontrolled acts.
Venez visitez
notre site web
voillot-joaillier.fr
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