Definition of hetian jade

Hetian jade in the traditional narrow sense refers to jade produced in Hotan area of Xinjiang, which is known as "secondary material". Hetian jade in a broad sense refers to nephrite (real jade). China named all the stones with tremolite accounting for more than 98% as Hetian jade, which are within the national standards.

There are few impurity minerals in Hetian jade, generally 1%-3%, mostly around 1%. The mineral has a fine particle size, which is microcrystal and aphanitic. Tremolite minerals are fibrous, needle-like and leaf-like under polarizing microscope. The typical structure is felt-like, with uniform particle size and interwoven into carpet-like, which is an important reason for fine texture.

Extended data:

Optical properties of hetian jade

1, luster: Hetian jade can be oily luster, waxy luster or glassy luster. Grease luster is very soft, neither thick nor light, which makes people look comfortable and feel beautiful. Generally speaking, jade is pure in texture and good in luster; There are many impurities and the luster is weak. Generally, glossy and oily people have higher values, while glossy and dry people have lower values.

Transparency: the expression of the intensity of light. Hetian jade is translucent to opaque, most of which are slightly transparent and a few are translucent. There are three factors that affect the transparency, one is the intensity of light, the other is the thickness of jade, and the third is the intensity of light absorbed by jade.

Refractive index: The refractive index of Hetian jade is1.606—1.632 (+0.009, -0.006). Because it belongs to mineral materials, it is rare to read two values at the same time. Usually, it is measured by the point method at1.60—1.6006.1000060606 optical characteristics: heterogeneous aggregate.

4. Absorption spectrum: Hetian jade rarely sees absorption lines, but there are fuzzy absorption lines or absorption bands at 500 nm, 498 nm and 460 nm; There is an absorption line at 509 nm; Some hetian jade has double absorption lines at 689 nm.

5. Luminescence: nephrite is fluorescent and inert under ultraviolet rays, and generally does not glow.

Baidu encyclopedia-Hotan jade