Abstract:Shoushan Stone produced in Fuzhou City of Fujian Province is composed of Field Stone, Waterhole Stone, Sliderock Stone and Mountain Stone. Preliminary statistics show that there are 16 kinds of Field Stone, 12 kinds of Waterhole Stone, 18 kinds of Sliderock Stone and 118 kinds of Mountain Stone, amounting to 164 kinds. They are comprised mainly of dickite, nacrite, kaolinite or pyrophyllite.

Abstract:According to its determined mineral components, Shoushan Stone can be classified into nacrite type, dickite type, sericite type and pyrophyllite type. Based on a discussion on nomenclature of Tianhuang Stone, the authors hold that all the Shoushan Stone and seal stones produced in other areas which are up to the nomenclature of Tianhuang Stone should also be called Tianhuang Stone. The ore_forming age of Shoushan Stone determined for the first time by the authors with 40Ar-39Ar method is 133.44±4.69 Ma, which suggests that Shoushan Stone was formed through the replacement of volcanic rock by hydrothermal solutions which were derived from volcanic rock itself and migrated along faults or shatter zones after the eruption of acid volcanic rock in late Jurassic.

Abstract:Radish striae constitute an important symbol for identification of Tianhuang. By means of rock slice， XRD test and electron microprobe analysis, the author found that the mineral constituent of the radish striae is illite. The formation of radish striae lies in the mechanism that microcracks were formed in the primary rock of Tianhuang under tectonic stress and later filled with heterogeneous illite. The illite in the microcracks looks like fibre （radish striae） because of the obvious optical difference between illite in the microcracks and dickite as the main mineral constituent in the rock.

Abstract:According to tests on large quantities of “Tianhuang Stone" handicrafts collected and stored up by common people, the Tianhuang Stone can be classified into dickite type, pyrophyllite type, illite type and clinochlore type in the light of major mineral constituents. Radish striae, patterns and cortexes do not constitute the prerequisite for the identification of Tianhuang Stone. As the nomenclature of Shoushan Stone and Tianhuang Stone should be in line with the international criteria, the author suggests that the dual-naming method combining the mineral name and tradition name be adopted. Tianhuang Stone contains some other components besides dickite and/or nacrite, and hence further related geological investigation and test should be conducted in future.

Abstract:Changhua Tianhuang Stone from Yuyan mountain area of Changhua in Zhejiang Province is a new species of Tianhuang Stone. Mineralogical studies of 68 samples show that Changhua Tianhuang Stone is composed of dickite and kaolinite, and may contain such auxiliary minerals as quartz, alunite, sericite, limonite and pyrite, but with no nacrite. Changhua Tianhuang Stone formed under the geological conditions similar to those of Shoushan Tianhuang Stone, and has such identification characteristics of Tianhuang Stone as surface, shape, color, texture, radish lines and red crack. Changhua Tianhuang Stone is different from Shoushan Tianhuang Stone in mode of occurrence, size, shape, and mineral components.

Abstract:Changhua Tianhuang Chicken-Blood Stone, a new variety of Tianhuang Stone, is divided by some people into two categories by its appearance, namely “Dong Di" Tianhuang Chicken-Blood Stone and “Gang Di" Tianhuang Chicken-Blood Stone. Based on analytical means such as EMPA, XRD, IR and chemical analysis, the authors studied Changhua Tianhuang Chicken-Blood Stone from Yuyanshan in Fujian Province. The results show that “Dong Di" Tianhuang Chicken-Blood Stone is mainly composed of dickite with a small amount of talc, while “Gang Di" Tianhuang Chicken-Blood Stone is mainly comprised of alunite with small amounts of dickite, quartz albite and talc. According to the general concept of Tianhuang, the authors believe that the “Dong Di" Tianhuang Chicken-Blood Stone can be categorized as “Tianhuang Chicken-Blood Stone", whereas the “Gang Di" Tianhuang Chicken-Blood Stone may be only defined as “Changhua Chicken-Blood Stone" and cannot be called Tianhuang because of its mineralogical characteristics.

Abstract:“Tianhuang" is the name of a kind of stone regarded as the most valuable of all stone sculpture materials in China. The Tianhuang Stone has been recognized as the emperor of stone, and its resource has been used up after thousands of years of mining. Since a lot of Tianhuang imitations appear on the market, identifying Tianhuang is becoming more and more important and difficult. Identifying Tianhuang in the past relied mainly on naked eyes through observing shape, cortex, “red pattern", “radish striae" （fine lines constitute the pattern of radish）and texture. With the employment of modern scientific instruments such as FTIR, polarized microscope, X-ray diffraction meter and scanning electronic microscope, there has appeared new understanding on identifying Tianhuang. Tianhuang consists chiefly of dickite and nacrite, and its cortex and core have the same mineral components, as shown by analytical results of infrared spectrometer and X-ray diffraction meter. Therefore, the combination of both traditional observation and modern instrument analysis seems to be an effective means for accurate identification of Tianhuang.

Abstract:At present, there exist quite a few troubles in the definition and identification of Tianhuang, such as excessive generalization and misuse of the name of Tianhuang, variance of the measurement criteria for identification of Tianhuang. This paper presents several important problems which deserve full attention in the correct identification of Tianhuang, emphasizes the importance of Tianhuang's secondary characteristics for its identification, and expounds the key points in distinguishing real crust from fake crust.

Abstract:X-ray diffraction method was employed to analyze twelve Tianhuang samples, which include one Qingtian Stone sample, nine Shoushan Stone samples and two Changhua Tianhuang Stone samples. The results show that Qingtian Stone consists of pyrophyllite（58%）, sericite (36.1%) and kaolinite (5.9%), Changhua Tianhuang Stone is composed of dickite, and Shoushan Stone is comprised respectivelyof dickite, kaolinite, pyrophyllite and sericite.

Abstract:This paper makes a brief description and analogy of Shoushan Tianhuang Stone and its similar seal stone, and discusses some problems concerning the difference between Shoushan Tianhuang Stone and Changhua Tianhuang Stone as well as between Shoushan Tianhuang Stone and the sliderock stone and cave stone of the same parent rock. The authors hold that, no matter where the producing area is and what the shape looks like, unified classification, naming and grading of the seal stone can be made in accordance with the major minerals so long as the seal stone is of high quality.

Abstract:Larderite is a precious material for sealing and carving. Having found some specimens similar to larderite in lots of larderite carving and ornament markets, the authors tested their refractive index, specific gravity and Mohs' hardness and examined their U-V fluorescence and characteristics under microscope and in hydrochloric acid. Nevertheless, the data obtained are not convincing enough to determine the mineral names of the specimens. Assisted by infrared spectra (strong and keen peaks at 3698 cm-1, wide bands in 3500～3400 cm-1 mean stretching vibration of—OH，the peaks at 560 cm-1 and 451 cm-1), the authors identified the specimens as brucite. The energy dispersion X ray fluorescence spectra (EDXRF) have also verified the conclusion.