What Is Jade Gemstone

Jade is a tough, compact, typically green gemstone that has been highly valued for its beauty and has been carved into various objects since ancient times. There are two main types of jade: jadeite and nephrite. Both minerals have been used to create jewelry, ornaments, and sculptures. Jadeite is a silicate of sodium and aluminum and is classed as a pyroxene, while nephrite is a silicate of calcium and magnesium belonging to the amphibole group of minerals and is properly regarded as tremolite.

How Jade is Formed

The formation of jade is a lengthy and intricate geological process involving multiple geological actions. 

Dolomite Deposition Stage: In the late Mesoproterozoic Era (about a billion years ago), along the southern edge of the Tarim Ancient Land, which is where the northern edge of the Kunlun Mountains is located today, there was a shallow sea area with a large amount of carbonate sedimentation, including dolomites rich in magnesium, which are one of the main sources for jade formation.

  1. Dolomite Metamorphism Stage: At the end of the Proterozoic Era, during the Sinian Period, the Tarim Movement caused intense folding and faulting activities, leading to the formation of the Tarim Continent. In this widespread regional metamorphism, dolomites were transformed into dolomitic marbles.
  2. Dolomite Metasomatism and Alteration Stage: Over 200 million years ago, during the Late Carboniferous to Late Permian of the Paleozoic Era, a global tectonic event known as the "Hercynian Orogeny" occurred. Along the southern edge of the Tarim Continent, there were intense faulting activities and magmatic activities. Along the faults, intermediate intrusive rocks intruded into the dolomitic marbles. The contact metasomatism and alteration led to the formation of jade's material conditions.
  3. Jade Formation Stage: During the late Hercynian period, when the intermediate acidic dykes intruded into the altered dolomitic marble, contact metasomatism occurred again. Under the right geological conditions (around 300-350 degrees Celsius, less than 2.5 kbar, and certain shear stresses), jade is finally formed.


What are the constituents of jade?

  • Nephrite: The main chemical composition is hydrous calcium magnesium silicate, and its mineral components are primarily composed of a special aggregate of the amphibole group. Hetian jade, a representative of nephrite, mainly consists of tremolite (Ca2Mg5(Si4O11)(OH)2) and actinolite (Ca2(Mg,Fe)5(Si4O11)(OH)2), with theoretical chemical compositions including: SiO2 59.169%, CaO 13.850%, MgO 24.808%.
  • Jadeite: Jadeite is a sodium-aluminum silicate belonging to the pyroxene group. Gem-quality jadeite is known as jade. Its chemical formula is NaAlSi2O6, indicating that jadeite contains sodium (Na), aluminum (Al), silicon (Si), and oxygen (O). In addition, jadeite may also contain trace amounts of other elements such as iron, chromium, and manganese, which contribute to its color variations.
  • General Composition of Jade: The chemical composition of jade is rich and diverse, with silicon dioxide (SiO2), aluminum oxide (Al2O3), sodium oxide (Na2O), etc., as the main components.
  • Trace Elements: Jade contains a variety of trace elements, such as zinc, iron, copper, manganese, magnesium, cobalt, selenium, chromium, titanium, lithium, calcium, potassium, sodium, etc., which give jade its rich colors.
  • Other Components: The definition of jade is broad, including various textures and colors of pyroxene group sodium-aluminum silicate mineral fibrous aggregates.

What is the most famous jade in the world?  

 Hetian jade, also known as 和田玉, is a famous traditional jade from China, renowned for its unique texture and profound cultural significance. It is mainly produced in the Xinjiang region of China and is also found in other places such as Qinghai, Russia, and Korea. Hetian jade has been cherished by the Chinese people since ancient times and is considered a witness to Chinese culture. Among the more than 20 countries and regions where it is produced, Xinjiang Hetian jade is particularly favored for its texture and color.

 

Reference

  1.  Shi, Guanghai (2019). ""软 玉 "一 词 由 来 、争 议 及 去 "软 "建 议 [Origin and controversy of the term "软玉 (Ruan Yu soft jade)" and a proposal to remove the word "软 (Ruan soft)" from "Ruan Yu"]". Earth Science Frontiers. 26 (3): 163–170. doi:10.13745/j.esf.sf.2019.5.25. Retrieved 5 December 2023.
  2. ^ Gem News, Gems & Gemology[page needed]
  3. ^ Bale, Martin T. and Ko, Min-jung. Craft Production and Social Change in Mumun Pottery Period Korea. Asian Perspectives 45(2):159–187, 2006.
  4. ^ Jump up to:a b Hunter, Sir William Wilson and Sir Richard Burn. The Imperial Gazetteer of India, Vol. 3. Oxford, England: Clarendon Press, Henry Frowde Publishers (1907), p. 242
Back to blog

Leave a comment

Please note, comments need to be approved before they are published.