The identification and appreciation of China ancient jade is the focus of this lecture, and it is also the most concerned issue for many ancient jade collectors. According to his years of experience in studying and appreciating ancient jade, Mr. Qu summarized it as "four views".
Jade is expected to look at it. When you get an ancient jade, you should first judge whether it is jade or stone, and then judge the category and origin of the jade. According to experts' research, the vast majority of jade materials used before Shang Dynasty in China are local jade materials collected nearby, among which serpentine (Xiuyan stone) jade, quartzite jade and serpentine marble are typical and extensive, as well as dushan jade in Nanyang, Henan and Hetian jade in Xinjiang. Hetian jade has been widely used in ancient jade articles since the late Shang Dynasty, especially in the Spring and Autumn Period and the Warring States Period. All the famous products or ornaments with particularly exquisite workmanship in the above historical periods must be excellent Hetian jade. Therefore, we should first judge ancient jade by the times, and the characteristics of the times are called a basic method to judge jade. For example, an ancient jade product before Shang Dynasty was made of Hetian jade, which may be a "lie". For another example, a well-made Warring States jade is made of low-grade miscellaneous jade or colored stones, and there are some strange things in it, which requires you to have as much historical knowledge as possible.
In addition, jade collectors should be good at summing up experience, so as to identify some "substitutes" from various ancient jade. For example, Hetian jade, whether it is white jade, sapphire, jasper or others, will have "cotton" or "floc" in its body, while Qinghai Shuibaiyu, which is often used to "pretend" Hetian jade, does not. Xiuyan jade is oily and much harder. The hardness of Dushan stone is close to that of Hetian jade, but it has a bright glass luster after pondering. The acquisition of the above experience depends on the long-term identification and appreciation process. In addition, there is a simple method to identify jade. The hardness of jadeite is usually between 4 and 6 degrees. We can use the bronze key that we carry with us (the hardness is generally around 4 degrees) to carve on jade. If the scratches can be carved, it means that the stone is not jade if its hardness is less than 4 degrees, while those above 4 degrees are within the scope of jade.
Double audience type. It is a very rigorous and exquisite thing for the ancients to make jade articles, which have relatively fixed models and styles in different times. Moreover, the changes of ancient jade and decorative patterns are also very slow. As long as we truly master the characteristics of jade articles and decorative patterns in various typical historical periods, we can quickly determine the age of jade articles and judge their authenticity. Generally speaking, the number of "famous and heavy objects" in Chinese jade is very limited, and because it is handmade, there is often only one work of art, so when you get a "famous ancient jade", you should observe it carefully and study any minor differences repeatedly. It is best to consult relevant experts for identification, otherwise it will be easy to "punch a hole" if you are not careful.
Third, look at the characteristics of workmanship. However, the hardness of the materials used in jade carving is mostly above 4.5 degrees, so it can't be carved directly with a knife, and instruments should be used to drive the medium to grind. In ancient times, the only tools for making jade were "grindstones", sand, sculptors with blunt edges and drill bits, and they were all done manually. However, mechanical processing is widely used in modern jade making, the former is slow, and the latter's high-speed production process will inevitably bring completely different processing marks to jade itself, which is also one of the important basis for identifying ancient jade.
Fourth, look at Qin color. The color of Qin jade, just like the tree rings, is the symbol of the era of jade production. How to distinguish the natural color of jade from artificial erosion dyeing is the key to distinguish the authenticity of jade. The natural color of jadeite is determined by different mineral components and generally does not change. Among them, the natural basic color gradually changes color from the inside out, and goes deep into the muscle to form calcification. Even multi-colored stones will have gradual and natural transition marks. Artificial ooze color is the color corroded by some organic or inorganic substances, and generally only adheres to the surface of jade. This artificial color covers the whole jade instead of a certain part. Some works that are not so brilliant can immediately reveal their flashy essence as long as they are irradiated with light.