Cobs are the original "treasure coins." Struck and trimmed by hand in the 1500s through 1700s at Spanish mints in Mexico, Peru, and Colombia (among others), silver and gold cobs are handsomely crude, nearly all with a cross as the central feature on one side and either a coat-of-arms (shield) or a tic-tac-toe-like "pillars and waves" on the other side. Silver cobs are known as "reales" and gold cobs are known as "escudos," with two 8 reales (about 27 grams each) equaling one escudo. Some cobs were struck with a date, and most show a mintmark and an initial or monogram for the assayer, the mint official who was responsible for weight and fineness. Size and shape were immaterial, which means that most cobs are far from round or uniform in thickness. Cobs were generally accepted as good currency all around the world, and were the exact coins pirates referred to as "pieces of eight" (8 reales) and "doubloons" (any gold cobs but originally 2 escudos). Their design and history have made cobs a very popular choice for jewelry.