In the middle of Preble County, surrounded by the small town of Eaton and the cornfields beyond, stands an anomaly: Silfex. An anomaly because, as one of only a handful of U.S.-based companies that grow silicon crystals, you might not expect to find it here. Yet, Silfex has managed to grab more than half the world-wide market for custom silicon parts used in machines that make memory and logic components -- at the same time other U.S.-based companies have found the required investment too daunting or been content to leave the business to foreign firms. Silfex employs some 250 in Eaton and another 50 at a sister plant in China.