Western North Carolina has the greatest variety of minerals in the country. Beginning in the 1860s, mica and feldspar were the money minerals, and North Carolina mica was considered the best in the world. One of mica's characteristics is that it is so hard that it will not burn. Feldspar is even harder. It can be melted but will not become fluid. Mining these two substances in earlier times involved great risk to the men who dug them from the earth. Unlike coal miners, these men are hardly mentioned in the historical literature, mainly because they were not unionized and didn't keep personal records. Haines discusses the men who dug the minerals from pre-Civil War days through World War II.