Zinc is found as a mineral in the earth's crust, usually associated with other base metals such as copper and lead. Zinc deposits are widely distributed throughout the world. The mineral found in massive deposits, where by far the largest tonnage occurs, usually has a high iron impurity content. This ore, known as marmatitic zinc, may have as much as 10% iron with zinc being only 40-45% in the concentrate. The large sources are Canada (British Columbia), USA (Utah, Colorado, Idaho), Peru (Cerro de Pasco Mine) and Australia (Broken Hill). The other common sulfide mineral is sphalerite, found in vein type deposits. The largest producers of this ore are Canada (Ontario and Quebec), USA (Missouri), Peru (Central Andes) and Japan.