metamorphic
Nephrite Jade
Ca2(Mg, Fe)5Si8O22(OH)2 (Actinolite/Tremolite series)
Hardness: 6-6.5 (Mohs scale); Color: Creamy white to sage green, often mottled; Luster: Vitreous to greasy; Structure: Interlocking fibrous (monoclinic); Cleavage: Indistinct; Specific Gravity: 2.90–3.03.
- Hardness
- 6-6
- Color
- Creamy white to sage green, often mottled
- Luster
- Vitreous to greasy
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-6.5 (Mohs scale); Color: Creamy white to sage green, often mottled; Luster: Vitreous to greasy; Structure: Interlocking fibrous (monoclinic); Cleavage: Indistinct; Specific Gravity: 2.90–3.03.
Formation & geological history
Formed through the regional metamorphism of magnesium-rich limestones (dolomites) or ultrabasic rocks. It is found in deposits ranging from the Precambrian to the Cenozoic era, typically in high-pressure, low-temperature subduction zones.
Uses & applications
Extensively used in jewelry (cabochons, beads), decorative carvings, and sculpture. Historically used for tool making (axes, blades) due to its extreme toughness/fracture resistance.
Geological facts
Nephrite is tougher than steel due to its densely felted, interlocking fibrous structure. It has been a cornerstone of Chinese culture for over 5,000 years, where it was considered 'the imperial gem'.
Field identification & locations
Identify by its waxy/greasy luster and extreme toughness (it does not chip easily). It feels heavier than common quartz pebbles of the same size. Found commonly in British Columbia, New Zealand, Russia, and Wyoming (USA). Look for translucent edges when held to high light.
More like this
