A visitor from the 19th century would be amazed to see the large, perfectly round, lustrous pearls available today, so unlike the irregular pearls of earlier eras. When cultured pearls first appeared on the market in the early 20th century, many people viewed them as second-rate "imitation" gems. Today, however, modern culturing techniques can produce pearls that rival or exceed natural pearls in size and beauty. Still, such pearls represent a small fraction of the cultured pearls made today, so assembling a stunning necklace like those below is a remarkable accomplishment that often requires many years.