1. Artificial cultivation: Callicarpa formosana is an artificially cultivated variety with high survival rate and high yield, which will not cause short supply and low price.

2. Market demand: Compared with traditional white or black pearls, the market demand of purple pearls is lower, and people are more interested in pearls with traditional colors such as white, pink, black and gold, which is more in line with the aesthetic and aesthetic value of traditional pearls.

3. Color stability: Purple pearls will gradually lose color under long-term sun exposure or other environmental conditions. In contrast, white or black pearls can maintain a stable color and are more favored by the market.