From Abstract: "The micaceous schist ores yielded concentrates containing 95 to 98 percent mica, with recoveries ranging from 70 to 83 percent. Part 1 of this report summarizes the process development work and demonstrates the feasibility of producing commercial-grade mica concentrates. The report also includes details of commercial beneficiation and grinding of mica. Also included in part 2 of this report are details of commercial mica production, including methods of mining, recovering, and grinding mica, and information on the production, uses, and prices of mica."

From abstract: The area comprising the first flood plain downstream from the headwaters of Knob Creek was one of three monazite placer deposits near Shelby, N. C., recommended by the Geological Survey for investigation by the Bureau of Mines as a joint effort by the above two agencies. Past production of monazite from the headwaters of this stream and its drainage of an area of known source rocks were factors influencing this selection. Drilling of the deposit was started on November 26, 1951, and completed December 29, 1951. Twenty-two churn-drill holes were completed to bed-rock on 112 acres of this flood plain for a total depth of 433 feet of vertical drilling.

From Introduction: "The investigations described in this bulletin are confined to a study of the washing characteristics of bituminous coals. The washing characteristics of coals from many of the most important coal-producing fields of the Eastern and Central States were examined."

From Introduction: "Figure 1 shows the location of sources that have been either exploited or seriously considered at one time or another, super-imposed upon a map indicating by small letters the order of consumption of K2O in the leading States; the amount used in these States, together with the percentage of the total consumption of potash used as fertilizer in the United States in 1939, is given in table 1. Figure 2 shows the domestic production and total consumption of potassium salts, in terms of tons of K2O, with the value per unit at the plants, for each year since 1913. Considered together, these two figures tell a significant story."