This book analyzes the characteristics of silicon (Si) in the Earth as well as its beneficial and harmful effects in life organisms. Silicon is a metalloid chemistry very common in the universe. On the Earth, it takes the form of sand and minerals such as quartz, amethyst, emerald and others. Si has similar structures than carbon and form part of the skeleton of some organism. Some silicates have been hypothesized that participated in the genesis of the first cells, and several evidences suggest that Si is important for normal growth and biological function in a variety of plants, animals and...