Nolans bore life of Arafura party

摘要

In 1794, Finnish chemist Johan Gadolin discovered a new metallic oxide in a mineral he obtained from the Ytterby quarry near his home in Stockholm. Gadolin named his oxide yttria after the quarry and referred to it as rare earth due to the fact that it was less common as other known earths at the time such as silica, lime and magnesia. Fifty years later, Gadolin's yttria yielded the element yttrium and the rare earth sector was bom. During the 19th century, the rare earth minerals were analysed and found to contain a group of 15 elements including the likes of lanthanum, neodymium and europium. Two hundred years later the unique chemical, catalytic, electrical, magnetic, metallurgicand optical properties these elements possess have made them virtually indispensable for many modern-day technological applications.