![crystallized talc from Luzenac in Arriege in France](https://www.patrickvoillot.com/wp-content/uploads/2021/03/talc-luzenac-arriege-france49.png)
colourless
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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![crystallized talc from Luzenac in Arriege in France](https://www.patrickvoillot.com/wp-content/uploads/2021/03/talc-luzenac-arriege-france49.png)
![violet taaffeite of Sri Lanka round cut](https://www.patrickvoillot.com/wp-content/uploads/2021/03/titanite-sphene-chromifere50.png)
![strontianite emerald cut](https://www.patrickvoillot.com/wp-content/uploads/2021/03/strontianite-taille-emeraude53.png)
![staurolite from Brazil oval cut](https://www.patrickvoillot.com/wp-content/uploads/2021/03/staurotide-ovale-bresil56.png)
staurolite
ck_admin
March 24, 2021
It is named after his twins very frequently cross-shaped: the twin cross of St. Andrew (60 degrees) and that of the Greek cross (90 degrees), in Greek “stauros” means cross and “lithos”, stone, hence its name “cross stone”. Another twin “in wheel”shape exists in the
![cushion cut spinel from Tanzania](https://www.patrickvoillot.com/wp-content/uploads/2021/03/spinelle-coussin-tanzanie57.png)
![cushion cut sphalerite from Picos de Europa, Santander in Spain](https://www.patrickvoillot.com/wp-content/uploads/2021/03/sphalerite-coussin-espagne59.png)
sphalerite
ck_admin
March 24, 2021
Its name comes from the Greek “sphaleros” meaning traitor, deceitful, because in its black variety it looked like galena but did not release lead during fusion … and because of its brightness was also confused with the diamond. It is the major ore of zinc.