![oval cut kyanite from Nepal](https://www.patrickvoillot.com/wp-content/uploads/2021/03/cyanite-ovale-nepal197.png)
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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 …
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![oval cut kyanite from Nepal](https://www.patrickvoillot.com/wp-content/uploads/2021/03/cyanite-ovale-nepal197.png)
![rock crystal from Perou](https://www.patrickvoillot.com/wp-content/uploads/2021/03/quartz-cristal-de-roche-perou207.png)
rock crystal
The name quartz comes from a slavic word meaning “hard”. Rock crystal comes from the Greek “krystallos” meaning ice, because the ancients believed that it was “eternal ice”. It is a mineral, often regarded as a rock as it is widespread in various aspects and
![creedite purple crystals of Santa Eulalia, Mexico](https://www.patrickvoillot.com/wp-content/uploads/2021/03/creedite-potosi-santa-eulalia-mexique201.png)
![cushion cut iolite from India](https://www.patrickvoillot.com/wp-content/uploads/2021/03/cordierite-iolite-inde202.png)
iolite
It was also known as “dichroïte” (because of its strong dichroism) or “iolite” (because of its purple color), the anglo-saxons still call it by that name. It honors the name of the French geologist Cordier, Professor at the National Museum of Natural History in Paris.
![rose carved in coral from Torre del Greco, Italy](https://www.patrickvoillot.com/wp-content/uploads/2021/03/corail-rouge-rose198.png)
coral
For the geologist, the mineralogist and the gemologist, it is neither a mineral or a fossil, or even a rock. This is the central limestone axis around which small polyps have developed, they secrete it and shelter there. These are animals of the Coelenterata phylum
![colemanite crystal from California in U.S.](https://www.patrickvoillot.com/wp-content/uploads/2021/03/colemanite-cristal-californie-usa203.png)
colemanite
It pays tribute to W. Coleman (1824-1893), founder of the borax industry in California.