Nephrite is one of the two mineral species known as Jade, the other being Jadeite. It is a silicate of calcium and magnesium, with the chemical formula Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂. Here are some detailed points about Nephrite:

• Mineral Composition: Nephrite is a type of Actinolite or Tremolite, which are both members of the amphibole group of silicate minerals. Its color varies from creamy white to green, often with subtle shades of grey, yellow, or brown.
• Physical Properties:
  • Hardness: Nephrite ranks between 6 to 6.5 on the Mohs Scale of mineral hardness.
  • Density: Its specific gravity ranges from 2.9 to 3.1.
  • Luster: It has a vitreous to greasy luster when polished.
  • Transparency: Nephrite is typically opaque but can be translucent in thin sections.
  • Fracture: It exhibits splintery to fibrous fracture.
• Formation: Nephrite forms in metamorphic rocks under high pressure and low to medium temperature conditions. Common locations for Nephrite deposits include:
  • New Zealand, where it's called Pounamu.
  • British Columbia, Canada.
  • Regions in Siberia, Russia.
  • Areas in China and Taiwan.
• Historical Significance:
  • In Ancient China, Nephrite was considered the "stone of heaven" and was used for creating intricate carvings, tools, and ceremonial objects. It symbolized virtue and was associated with immortality.
  • Nephrite was also used by the Maori people of New Zealand for making tools, weapons, and ornaments known as Hei-tiki.
• Cultural Impact:
  • Nephrite's toughness and beauty made it a preferred material for ancient artisans, leading to its widespread use in various cultures for both utilitarian and ceremonial purposes.
  • It has been historically used for its supposed metaphysical properties, including protection against kidney diseases, which is why the name Nephrite comes from the Greek word 'nephros', meaning kidney.
• Modern Use:
  • Today, Nephrite is used in jewelry, often as cabochons or beads, due to its toughness and attractive appearance.
  • It's also a popular material for ornamental carvings, sculptures, and decorative items.
• Distinction from Jadeite:
  • While both Nephrite and Jadeite are called Jade, they differ significantly in composition, with Jadeite being a pyroxene, not an amphibole.
  • Jadeite is generally more valuable and rarer than Nephrite, often commanding higher prices in the gemstone market.

References:

• Gemdat.org - Nephrite
• Mindat.org - Nephrite
• Minerals.net - Nephrite
• GIA.edu - Jade

Related Topics:

• Jade
• Jadeite
• Actinolite
• Tremolite