![gypsum crystals from Spain](https://www.patrickvoillot.com/wp-content/uploads/2021/03/gypse-cristaux-espagne167.png)
pearly
Je vous emmène à travers mes vidéos découvrir mon expérience acquise depuis plus de 30 ans a silloner le globe entier à la recherche de pierres précieuses, de rencontre mémorables mais aussi de difficulté parfois …
actualités
Categories
![gypsum crystals from Spain](https://www.patrickvoillot.com/wp-content/uploads/2021/03/gypse-cristaux-espagne167.png)
![oval cut dolomite from Brazil](https://www.patrickvoillot.com/wp-content/uploads/2021/03/dolomite-ovale-bresil188.png)
![oval cut kyanite from Nepal](https://www.patrickvoillot.com/wp-content/uploads/2021/03/cyanite-ovale-nepal197.png)
kyanite
Its name recalls its dominant color : blue in Greek (cyan). Sometimes colorless, but generally blue to bluish green, this gemstone has a hardness ranging, with its texture in plans, from 4.5 (direction of elongation) at 6 to 7 (perpendicular to the elongation). It also
![cancrinite fancy cut](https://www.patrickvoillot.com/wp-content/uploads/2021/03/cancrinite-taille-fantaisie222.png)
cancrinite
It was identified in 1839 by a German mineralogist and named in honor of the Russian Finance Minister George Kankrin (1774-1845). This stone is particular : it is a silicate but effervesces with acid because it contains carbonates.
![calcite from Russia emerald cut](https://www.patrickvoillot.com/wp-content/uploads/2021/03/calcite-taille-emeraude-russie223.png)
calcite
It is known since antiquity, its name comes from the Greek “khalx” for lime. Identified and analyzed from the seventeenth century and then by Rene-Just Haüy to its easy cleavage. Called Iceland spar, the crystals exhibit the phenomenon of double images: a feature seen through
![twinned boleite crystals from Boleo, Mexico](https://www.patrickvoillot.com/wp-content/uploads/2021/03/boleite-cristaux-boleo-mexique231.png)