从科学层面鉴定古玉

中国玉器不仅是艺术品,也是中国历史记载的实物证据。前面的声明只有在这些文物是真实的时才是真实的。 因此,除了玉器质量和做工精湛等其他因素外,玉器的价值取决于其真实性。因此,玉石鉴定在中国玉石研究中至关重要。

古玉的鉴定是客观而科学的。 一般而言,古玉可透过观察玉器本身是否具备下列物理化学特性加以测定:差异风化,扩散沁色(玉器表面受到不同矿物随着玉之纹理结构,侵蚀渗透至玉器内部,所形成深浅层次不同 的颜色,溶蚀孔(玉器埋在在地下时,表面若接触到不同的化学物质,所形成之不规则孔洞,一般是洞口小,洞内大且有角砾岩),晶体曝 是古玉受外界矿物影响所形成低于玉器表面的反光体(又称云母片)),次生长晶体(次生结晶体是古玉受外界矿物影响所形成高于玉器表面凸起的物体 为针状)而与古玉表面平行,这些针状晶体系覆盖于刀工纹饰之上,说明了玉器雕琢在先,次生结晶体的形成在后。

Scientific Jade Authentication

Chinese jade artifacts are not only pieces of artworks but also the physical evidences of the records of Chinese history. The previous statement is true only if these artifacts are genuine. Therefore, the value of jade artifacts depends on its genuineness in addition to other factors such as quality of jade and mastery of workmanship etc.. As a result, jade authentication is of paramount importance in the Chinese jade studies.

S__2826298There were many writings on the jade authentication theory and practice since the Song and Yuan dynasties (906 CE -1379CE) in the Chinese history. Among them, the most popular two works were published in the late Qing and early Republic periods. Today, although there are many jade authentication methodologies that appeared in the publications, there are a lot of disagreements on the accuracy of the various methodologies and the theories behind them. Many of the methods used by professional researchers and collectors in the authentication of Chinese antique jades tend to be very subjective, often rely heavily on appearance, feeling, etc…

In the 1995 jade’s authentication conference held in Taipei,  Prof. Tsien, H. H.  proposed aS__2826299 scientific approach on jade’s authentication in the article of Mineralogical Studies of Archaic Jades. Since then, the scientific method for jade’s authentication has gained wide acceptance from both academia and professionals in Taiwan and other parts of the world.  According to Prof. Tsien, the steps for authentication of jade antiques consist of medium authentication, jade antiquity authentication  and period verification.  The first two steps of jade’s authentication method are fully explained in the following sections. For the discussion of the period verification, please refer to the information on motif and carving style for a particular period shown in the A Comprehensive Handbook of Chinese Archaic Jades or go to timeline of chinese jade-neolithic period and timeline of chinese jade-the dynasties. S__2826300 Jade antiquity authentication may be verified through evidences of certain physical and chemical characteristics. These evidences consist of dissolved pits, cleaving veins, differential weathering, diffusive markings, exposure crystals, deterioration marking and secondary additive crystal planes. In addition, mineral attachments such as gold or silver placer may be served as an evidence that the sample jade has been buried under the ground. These physical and chemical phenomena are formed by nature through ages and cannot be made by human beings. The authentication of these antiquity evidences is of paramount importance in the whole process of the scientific method of antiquity jade authentication.

Warring States Jade Priests, Height 29 and 30 cm, width 11.4 and 11.8 cm

 

Carved with white jade, the objects are couples of male and female priests. Wearing hats decorated with animal horns, the priests stand on special stand with dragons attached on the two sides and phoenix head with loose ring hangs on the beat. The priests  are practicing a worship with thumb and index fingers raising up. Antiquity evidences include differential weathering, diffusive markings, dissolved pits and cleaving veins. Workmanship of these unique and rare priests are excellent.