They are Buddhist amulets, worn for centuries in Thailand, and many other parts of Asia, to ward off evil spirits and guarantee good luck and a healthy life.

These days almost every Thai wears at least one, usually blessed by a monk. But tradition ends there for many modern collectors, who are as likely to pick up their amulets on-line and to pay with a credit card.  Indeed, the best amulets don't come cheap. An amulet that was made almost two centuries ago at Wat Rakang, a temple in Bangkok. The amulet from Wat Rakang is the most powerful. And it's very rare, hence the high price. Less sought-after amulets can cost as little as $10, but usually lack qualities like age, beauty and supposed supernatural powers.  Amulets are usually made of stone or clay (though gold, copper, jade and other materials are not unheard of), and usually display images of the Buddha or revered monks. Wearers carry them about their neck, often in small silver or gold boxes. The value of an amulet is affected by a number of factors: Who made it and where, the beauty of the image and just as importantly its reputation for bringing luck.