Lapis lazuli (derived from Latin) was known in ancient China as “qiu lin”, “jin jing”, “jin yu”, “qing dai”, etc. Buddhism, also known as Vainuri or Bi Liuli, is one of the witnesses of cultural exchange between the East and the West in ancient times. Data shows that lapis lazuli was introduced to China from Afghanistan through the Silk Road. It is usually produced as a collection, with a dense block like and granular structure. The colors are dark blue, purple blue, sky blue, green blue, etc. Lapis lazuli is still the main raw material for natural blue pigments.
Product Introduction
Lapis lazuli, its craft name is “Qingjin”. The Persian name for lapis lazuli is “Lashuwa’er”, the Arabic name is “Lashuwa’er”, and the Hindi name is “Lejiwa’er”, all of which refer to lapis lazuli.
Lapis lazuli has been loved by emperors throughout history due to its heavenly hue. The emperor used lapis lazuli to decorate the Temple of Heaven, yellow jade to decorate the Temple of Earth, coral to decorate the Temple of the Sun, and white jade to decorate the Temple of the Moon. The top of the court attire for fourth grade officials in the Qing Dynasty was made of lapis lazuli.
Lapis lazuli usually has two meanings.
Firstly, it refers to alkaline aluminosilicate minerals. Chemical formula (Na, Ca) 7-8 (Al, Si) 12 (O, S) 24 [SO4, Cl2 (OH) 2]. Sodium is often partially replaced by potassium, while sulfur is replaced by sulfate ions, chlorine, and selenium. Due to the lack of thorough research on the mineral lapis lazuli, there are other different ways to write its chemical formula, such as (NaCa) 8 (AlSi04) 6 (SO4, cl, S) 2. At this time, the mineral is in an equiaxed crystal system with a refractive index of N=1.50, dark blue, blue violet, sky blue, light blue, or green blue.
Secondly, it refers to rocks mainly composed of lapis lazuli minerals, which contain a small amount of impurities such as pyrite and calcite in cryptocrystalline aggregates. The cleavage is not developed, the fracture surface is uneven, and the stripes are light blue. Under long wave ultraviolet light irradiation, it emits orange dot light, and under short wave ultraviolet light irradiation, it emits white fluorescence. Under the filter, it appears light red. Glass luster to wax luster, refractive index N=1.502~1.505, relative density 2.7~2.9. Lapis lazuli slowly releases hydrogen sulfide when encountering hydrochloric acid.
Lapis lazuli has a glassy to oily luster and a hardness of 5.5. Lapis lazuli has unique shades of blue, deep blue, light blue, and light cyan, which can be classified according to their different colors: turquoise, jujube, deep blue, and thick but not black; The content of deep blue and pyrite in Jinggelang jujube is higher than that of lapis lazuli mineral; The origin of the light blue color and white calcite containing stone jujube is named after the ancient saying that this stone was used as a fertility medicine. In ancient China, the burial of lapis lazuli was said to have been used to make burial objects for emperors, as it was believed to have a green color and was used to pave the way to heaven.
Good lapis lazuli has a deep blue and pure color, no cracks, delicate texture, and no impurities such as calcite. Both those without Venus (pyrite) and those with very beautiful Venus are of high quality.
The origin includes countries such as the United States, Afghanistan, Mongolia, Myanmar, Chile, Canada, Pakistan, India, and Angola. The lapis lazuli in Afghanistan is produced in the lapis lazuli bearing area of Badakhshan Province, with the Saresang deposit being the most famous. The genesis type of lapis lazuli jade deposits is contact metasomatism skarn type. [3] The lapis lazuli produced in Aguo has a uniform deep blue to sky blue color, with a very fine-grained cryptocrystalline structure mixed with trace amounts of pyrite, making it shine brightly under sunlight. Lapis lazuli is called a “treasure” by Arab Muslim countries.
Lapis lazuli can be used for both jade carving and jewelry making. China’s lapis lazuli carving craftsmanship is first-class, especially after the establishment of the People’s Republic of China. The lapis lazuli ornaments, mountain ornaments, pendants, jewelry and other products produced by Beijing Jade Factory were exported abroad. The ongoing war in Afghanistan has made it very difficult to import raw materials.
Appraisal method
Natural lapis lazuli can be seen under a magnifying glass with its granular structure, often containing pyrite spots and white calcite clusters.
Lapis lazuli is generally blue in color, and its color is determined by the amount of lapis lazuli minerals it contains. Good lapis lazuli has a deep blue and pure color, no cracks, delicate texture, and no impurities such as calcite. It can be made into jewelry, etc. If there are white stone lines or white spots interwoven, it will reduce the concentration, purity, and uniformity of the color, and the quality of the jewelry will decrease.
The texture of lapis lazuli should be dense, delicate, without cracks, and the distribution of pyrite should be uniform, resembling sparkling stars, which is considered a superior quality. If pyrite is locally distributed in patches, it will affect the texture of lapis lazuli jade, and the more obvious the cracks, the lower the quality grade.
