Job's tears are the grains of a tropical Asian grass, Coix lacryma-jobi. These grains have a number of uses, from foods to ornaments, and they appear to have been harvested and cultivated for thousands of years. Many Asian markets sell them in their grain sections for cooking. Beaders and craftspeople also use the grains, and they may be found at beading and craft stores for this purpose.
The common name for Job's tears comes from their distinctive teardrop shape, although the tears are sometimes ascribed to different people, such as Mary's tears, Christ's tears, and so forth. The plant does not appear to have any religious significance, despite the Biblical references in its common names, although the grains are sometimes used as the beads in rosaries. The scientific name suggests that the plant was originally known as Job's tears, whatever else it might be called, since this is what lachryma-jobi means.
Many people mistakenly believe that these grains are a form of barley, probably because many markets label them as “Asian barley” or “Asian pearl barley.” In fact, barley is in an entirely different botanical genus, although the two plants are in the same family. Like barley, Job's tears are dense, rich in minerals, and easy to use in a variety of recipes, so the case of mistaken identity can be forgiven. The plants are also cultivated as ornamentals, incidentally, and Western gardeners may not be aware that the large grains on these grasses are perfectly edible.
As a food, Job's tears can be used like any other grain in soups and gruels, and they can also be ground to make flour. In Asia, the grains are believed to be beneficial for joint pain, and they are sold in a polished white form and in an unhulled brown form. Unhulled tears are more readily available in Japan, where they are called juzudama.
In crafts, these grains are used to make beads, and they may be dyed or carved to enhance their artistic value. It is generally not a good idea to eat those that are designed for crafting, since they can be treated with various substances to make them more durable. Many varietals of the plant actually grow naturally with a small hole, making them suitable for stringing as beads.