Olivine has the formulae (Mg,Fe)2SiO4 and a relative hardness of 7. It's name is derived from the characteristic olive green colour. A common rock forming mineral. A clear green variety is called peridot and has some uses as a gem.
Hear it on YouTube. Here's a piece that many people know, and rightfully so! This famous classical piece from the romantic period is one of those pieces that has the ability to make anyone feel happy. Composed in the 1920s, for a ballet, the piece was an instant success.
The history of Waltz. The Waltz is the oldest of the ballroom dances, dating from the middle of the Eighteenth Century. The German Lander, a folk dance, is supposed to be the forerunner of the Waltz. During this time period a dance developed which was called the Walzer, a word owing its origin to the Latin word Volvere, which indicates a rotating motion.