Basic Characteristics of Clinochlore Jade (Qianshanhuangdong Stone) and the Discussion on Related Issues

Qianshanhuangdong stone is a mild, dense, brownish-yellow to yellowish-brown clinochlore jade that has been discovered in recent years with high artistic and economic value. Produced in Section 3 in the Dashiqiao Formation, Liaohe Group, the primary Qianshanhuangdong stone occur as nested, sac-shaped, lenticular, and quasi-lamellar orebodies. The secondary monoliths that have been developed and utilized are distributed in the alluvial-pluvial deposits and farmlands on both sides of the gullies and riverways around mountains of the primary mineral veins several kilometers nearby. The research show that Qianshanhuangdong stone mainly consists of clinochlore, which is extremely rich in Mg and poor in Fe, and contains trace minerals such as quartz, phlogopite, talc, rutile, etc. Due to the chemical composition of the main mineral, the petrochemical characteristics of the stone are correspondingly rich in Mg and poor in Fe; the total amount of rare earth in Qianshanhuangdong stone is extremely small, and the degree of fractionation of light and heavy rare earth is also low. Compared with the primitive mantle, the large ion lithophile elements K, Ba, and Sr of Qianshanhuangdong stone have different degrees of loss; high field-strength elements such as Nb, Ta, Zr, Hf, Th, U, and Ti tend to be enriched. Qianshanhuangdong stone should not be called Tianhuang because of their different main constituent minerals. By the quantitative phase determination of minerals with large instruments such as infrared spectroscopy, it can be effectively distinguish Qianshanhuangdong stone and Tianhuang. Although there are some stones that mainly consist of serpentine, talc, or carbonate from the same origin and are somewhat similar to the clinochlore one in appearance, they still cannot be called Qianshanhuangdong stone ever.