The oiliness of Hetian jade is not a simple "shining", it contains the dual concepts of vision and touch, that is, the visual oiliness and tactile oiliness of jade.
Visual oiliness
Visual oiliness (it looks really oily) refers to the oily luster of Hetian jade, which gives people a moist feeling. This luster is very soft, neither the crystal transparency caused by strong light nor the waxy texture caused by weak light. Because of the special structure of jade molecules, it has a special diffuse reflection effect on light.
The closer the particles are arranged between jadeites, the stronger the luster, and the harder the jadeite, the harder the luster. The luster of jadeite needs to be "rigid", and the density of nephrite and hetian jade just matches the fine particles, resulting in a delicate and oily feeling and rich texture; At the same time, the matching of reflectivity, refractive index and transmittance is just right, which makes the transparency of jadeite between translucent and slightly transparent. There is a sense of transparency on the surface and an incomplete sense of transparency on the inside, just like concentrated animal fat.
Touching oil and touching oil means that when you touch the handle, your hands come into contact with Hetian jade, which is smooth but not greasy, like oil but not oily, and you can feel this delicate and moist.
Causes of greasy touch
Tactile oily refers to the oily feeling with slight resistance, just like holding a weight of oil in your hand, which will melt when you push it with your hand. This is inseparable from the fineness of jade, that is, the diameter of crystal particles in jade. The structure is required to be thin and uniform, and the structure is invisible and intangible.
The oiliness of Hetian jade is influenced and determined by its crystal structure, particle size, compactness, reflectivity, transmittance, refractive index and surface smoothness.