Crystal from Hainan is arguably the best in China. Chiarman Mao's coofin in Beijing was built with Hainan crystal.
The luminous natural material is not only made into various kinds of jewels including necklaces, brooches and earrings, but apparently has medicinal benefits!
Sanya also prides itself on its beautiful, luminous crystal. Crystals have mysterious properties that can calm your nerves, improve your memory and health, and bring you luck. Most crystal products are smelted with crystal or at a temperature of 3,500℃ and are similar to natural quality. Beware however of man-made crystals made using lead that could be harmful to your health.
There are a number of ways to distinguish between man-made and natural crystals. Natural crystal can cut glass while man-made crystal cannot; natural crystal is cool and comfortable when you lick it; you can see double when you put a strand of hair under a natural crystal, due to its refractive properties, but this does not work with man-made crystal.