1. Average quality: In the market, the price evaluation criteria of turquoise are comprehensive factors such as color, porcelain and size, while the quality of Zhushan turquoise is average, which is also the main reason for its low price.

2. Large output: Zhushan turquoise has a large output, and the supply exceeds demand in the market, so the price is naturally lower.

In a word, Zhushan turquoise is cheap mainly because of its ordinary quality, large output and low price due to imbalance between supply and demand.