Q: What are jadeite, chalcedony and jadeite? What is the difference?

In China, jade is synonymous with beautiful stones. The ancients regarded jade as a treasure, and today people call precious jade Baoyu. China is a country of jade, but at present, there are differences in the definitions of jade, jade and precious stones in the domestic jewelry, archaeology and geology circles. At present, jade in the world refers to nephrite and jadeite (that is, jadeite, as we usually say), and other jade carving stones are collectively referred to as jade. Gem is a collection of one or more minerals with special optical effects, and most of them are single crystals of certain minerals, such as diamond, ruby, sapphire, emerald, opal, tourmaline, purple tooth black and so on.

First, jade

/kloc-in the second half of the 9th century, Demoures, a French mineralogist, divided China's "jade" into nephrite and jadeite (see "Emerald Chong Foreign Geological Science and Technology" No.2, 198 1). Emerald, commonly known as "Emerald" in China, is a rising star in traditional jade in China, and also the top grade in all modern jade.

Emerald, whether it is "mountain material" (primary ore) or "seed material" (secondary ore), is mainly a dense block composed of jadeite minerals. Under the microscope, jadeite minerals that make up jadeite are closely intertwined, forming a fibrous structure of jadeite. This compact fiber structure makes jadeite delicate and tough.

Jadeite is composed of silicate minerals of steel and aluminum. Pure jade is colorless or white. The chemical composition of the block is: silica accounts for 58.28%, sodium oxide accounts for 13.94%, calcium oxide accounts for 1.62%, magnesium oxide accounts for 0.9 1%, iron oxide accounts for 0.64%, and it also contains trace amounts of chromium and nickel. Among them, chromium is the main factor that makes jadeite green. Usually, jadeite contains 0.2 ~ 0.5% chromium oxide, and some of them reach more than 2 ~ 3.75%.

Emerald hardness 7, specific gravity 3.33. Refractive index of minerals: Ng= 1.667, NP =1.654; The discount rate is 0.0 12.

Common jadeite colors are white, gray, pink, light brown, green, emerald green, yellow-green, purple and so on. Most of them are opaque, partly translucent and glassy. According to color and texture, there are more than 20 varieties, such as ruby green, brilliant green, yellow sun green, sunny green, glass green, Ying Ge green, spinach green, shallow water green, light sun green, frog green, melon skin green, plum blossom green, blue-green, gray green, oil green, violet, lotus root powder land and so on.

Jade is clearly called jadeite in China, which probably started in Song Dynasty. The jadeite mentioned in Zhang Heng's Poems on Xijing, Ban Gu's Poems on Xi Du and Xu Ling's Poems on Yutai in the Six Dynasties may refer to jasper in nephrite, not jadeite. Because jadeite was not tested in the Tang Dynasty, Shan Li's Notes on Selected Works and Yan Shigu's A Visit to the History of Han Dynasty are unheard of. Recently, Joseph Needham, a British historian, said in the third volume of History of Science and Technology in China:/kloc-Before the 8th century, people in China didn't know about jadeite. Later, jadeite was imported from Myanmar to China via Yunnan. Not long ago, Soviet geologist Kivlinko also pointed out that the secondary jadeite deposits in Dumao, Panmao and Nannaimao in Myanmar were discovered in 187 1 year, and have been mined for 100 years, but they have not been mined. The primary jadeite in the Wulong Valley of Myanmar was mined as early as13rd century (late Song Dynasty and early Yuan Dynasty) (see foreign geological science and technology). However, among the palace treasures and unearthed cultural relics in China, jadeite before Ming Dynasty has not been found. Therefore, it has always been an unclear historical mystery when China people called jadeite jadeite and when Burmese jadeite was introduced to China. We expect archaeologists to make new discoveries to solve this historical unsolved case.