Silver is a whitish precious metal and has been used since about 4000 BC for various purposes such as money, silverware, jewelry and so on. Silver is measured in troy ounces. A troy ounce is 31.10348 grams.
Food Desert Locator from the USDA. GoodFood World Staff, May 4th, 2011. The official definition of a food desert is a low income census tract where at least a third of the residents are a mile from a supermarket or large grocery store.
Those criteria imply that they are have limited access to fresh, whole, nutritious food and may not be able to afford it, if they can get it. By applying these criteria, the USDA Food Desert Locator highlights those census tracts that are considered food deserts.