Hi guys, for those of you who are into gems and jades, the material used is Nephrite Jade mined in Canada where there are lots of Nephrite deposits. As you know Nephrite is the 'softer' type of Jade, compared to the super-hard Jadeite and for the most part, it is also cheaper--however not always. Some Siberian and Canadian Nephrite stones can be highly saturated (especially towards Green) and translucent and will therefore command high prices.
Anyway, what Jorg did with these buttons is nothing short of amazing. The craftsmanship, of course, in mind-blowing and to top it off just a great professional guy to communicate with. Never leaves you hanging, replies to emails within the same day.