Terra Cotta, California
Coal, along with clay deposits, was found on the site by John D. Huff in the late 1880s, and the Southern California Coal and Clay Company was formed to mine them. The town site of Terra Cotta was laid out and was given a post office on October 26, 1887. In May 1893 its post office was closed and moved to Lake Elsinore. A plant for the manufacture of sewer and water pipes was built using the coal to fire ceramic pipes in the four kilns. The finished product had to be shipped by wagon six miles through Lake Elsinore to the La Laguna rail station at the mouth of Railroad Canyon until 1896 when a spur line was built through Lake Elsinore and Terra Cotta to the new clay deposits in Alberhill. The coal mined was also used locally as fuel for the stamping mill at the Good Hope Mine and was shipped elsewhere in the state.
Mining industry of Angola
Angola is also rich in several other mineral resources that had not been fully exploited by the early twenty- first century . These include manganese, copper, gold, phosphates, granite, marble, uranium, quartz, lead, zinc, wolfram, tin, fluorite, sulfur, feldspar, kaolin, mica, asphalt, gypsum, and talc. The government hopes to resume mining in the southwest for crystalline quartz and ornamental marble. It has been estimated that 5,000 cubic meters of marble could be extracted annually for a period of twenty years. A state-owned company mined granite and marble in Huíla and Namibe Provinces, and in 1983 it produced 4,450 cubic meters of granite and 500 cubic meters of marble. Since then, the company has ceased production in order to re-tool with modern machinery. Quartz production, however, was suspended indefinitely because of the military situation in areas near the extraction sites in Cuanza Sul Province.