在1955年至1985年的三十年间,美国只有两个产蓝晶石的矿山。这两个公司之间的竞争控制着蓝晶石的价格。1985年,其中的一个矿山关闭,从此消除了本国内部的价格竞争。美国用于生产冶金工业耐火材料所消耗的蓝晶石大约占总消耗量的75％,15％用于玻璃工业,其余用于白色器皿,如火花塞绝缘体,催化剂 In the 30 years from 1955 to 1985, there were only two mines producing kyanite in the United States. The competition between the two companies controls the price of kyanite. In 1985, one of the mines was closed and the domestic price competition was eliminated. The kyanite consumed in the United States for the production of metallurgical industry refractory materials accounts for approximately 75% of the total consumption, 15% for the glass industry, and the rest for whiteware, such as spark plug insulators, catalysts