Rock crystal vase Rock crystal vase A rock crystal vase is a vase made of rock crystal, a type of hardstone carving. Such vases were rare, expensive, and decorated with gold and jewels, used by royalty in Europe. A rock crystal vase that probably originated in the seventh century was given to William IX of Aquitaine (the Troubadour) by a Muslim ally (probably 'Abd al-Malik Imad ad-Dawla). When Eleanor of Aquitaine, William IX's granddaughter, married King Louis VII of France in 1137, she gave him the rock crystal vase as a wedding present. The inscription on it says he, in turn, gave it
Tin content. Because of the higher specific gravity of tin dioxide, about 80% of mined tin is from secondary deposits found downstream from the primary lodes. Tin is often recovered from granules washed downstream in the past and deposited in valleys or the sea. The most economical ways of mining tin are by dredging, hydraulicking, or open pits. Most of the world's tin is produced from placer deposits, which can contain as little as 0.015% tin. About 253,000 tonnes of tin have been mined in 2011, mostly in China (110,000 t), Indonesia (51,000 t), Peru (34,600 t), Bolivia (20,700 t) and