An ornamental stone since antiquity, agate has been found in a variety of ancient Greek contexts, such as for Mycenaean jewelry and warriors' seal stones. Because it is hardy, often spectacularly colored, and polishes to a high shine, it has long been valued for decorative purposes. It is formed in alternating layers that produce the distinctive banding effect, of which there are many varieties worldwide. Freshwater pearls are real, cultured pearls, grown in lakes, rivers, as well as ponds, which make them an affordable choice for jewelry-making because they are easier to extract.