smoky quartz

Smoky quartz is a fine transparent stone belonging to the quartz species. It is dark brown to black in color. Its color is due to the natural irradiation of the aluminum impurities it contains. This irradiation can also be artificially reproduced in the laboratory.

Its hardness is 7 on the Mohs scale.

They naturally come from France or Scotland.

It is an attractive stone for jewelry thanks to its beauty, brilliance and durability.

Source:

https://fr.wikipedia.org/wiki/Quartz_fum%C3%A9