Mining in Afghanistan "List of Goods Produced by Child Labor or Forced Labor" in which Afghanistan appeared to be one of the 74 countries with noticeable incidence of child labor in the coal mining field. Afghanistan is known to have exploited its precious and semi-precious gemstone deposits. These deposits include aquamarine, emerald and other varieties of beryl, fluorite, garnet, kunzite, ruby, sapphire, lapis lazuli, topaz, tourmaline, and varieties of quartz. Corundum deposits (sapphire and ruby) in the country are largely exhausted, and very little gem quality material is found. The four main gemstone-producing areas are those of Badakhshan, Jegdalek, Nuristan, and the Panjshir
History of manifolds and varieties spaces with a differentiable or topological structure, while "variety" refers to spaces with an algebraic structure, as in algebraic varieties. In Romance languages, manifold is translated as "variety" – such spaces with a differentiable structure are literally translated as "analytic varieties", while spaces with an algebraic structure are called "algebraic varieties". Thus for example, the french word "" means topological manifold. In the same vein, the Japanese word "" (tayōtai) also encompasses both manifold and variety. ("" (tayō) means various.) Ancestral to the modern concept of a manifold were several important results of 18th and 19th century mathematics. The oldest