Blue celestina geodel (3.6kg) from Madagascar

This natural blue color is quite rare in nature. Its composition, a natural Strontium sulfate, and the shape of its often prismatic flattened crystals (such as Aquamarine) but sometimes tabular, have formed in a hydrothemal medium. Curiously, one of the industrial uses of Celestina is to enter into the composition of red dyes. While its name evokes of course the celestial color of the sky, especially for this beautifull piece. And when the crystals are as ilarge as in this geode, you can cut beautiful stones for jewelry, comparable to Aiguemarine A geode as we only find in Madagascar. that's the one under stephanie's magnifier on the group picture.