The overall quality of grains is affected by several factors, including growing practices, harvest date and type, post-harvest handling, storage management, and transport practices.

Metals are natural compounds of earth's crust, in which they are generally found in the form of metal ores, associated both with each other and with many other elements. They are also naturally present in the rocks washed by surface water and groundwater and in atmospheric dust.

A gemstone is a piece of mineral crystal that, when cut or polished, is used to make jewelry or other adornments.