
Metamorphic (low-grade)
Greenstone (possibly Basalt or Greenschist)
Greenschist (composed primarily of chlorite, actinolite, and epidote)
AI-generated identification · may be incorrectHardness: 6-7 on Mohs scale; Color: Dark forest green to grayish-green; Luster: Dull to waxy; Texture: Fine-grained, often smooth or water-worn; Structure: Non-foliated to weakly foliated.
- Hardness
- 6-7 on Mohs scale
- Color
- Dark forest green to grayish-green
- Luster
- Dull to waxy
Identified More metamorphic (low-grade) →
Explore Greenstone (possibly Basalt or Greenschist) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 on Mohs scale; Color: Dark forest green to grayish-green; Luster: Dull to waxy; Texture: Fine-grained, often smooth or water-worn; Structure: Non-foliated to weakly foliated.
Formation & geological history
Formed through the low-grade metamorphism of mafic igneous rocks (like basalt) under low temperature and high pressure. Often found in ancient orogenic belts or oceanic crust that has been subducted and exhaled.
Uses & applications
Historically used for making stone tools (axes and adzes) because of its toughness. Currently used for landscaping, crushed stone for construction, and occasionally for minor jewelry or cabochons if the color is vibrant.
Geological facts
Many Neolithic 'celt' axes were carved from greenstone due to its resiliency and lack of cleavage planes, making it difficult to shatter. In New Zealand, a specific type of greenstone called Pounamu is considered sacred by the Māori.
Field identification & locations
Identify in the field by its distinct green hue (visible when wet), high density, and hardness (it should not be scratched by a steel knife). Commonly found in riverbeds or coastal areas near tectonic plate boundaries.
More like this
Other metamorphic (low-grade) specimens
Grey River Stone (Quartz-rich Quartzite/Siltstone)
Quartzite / Meta-siltstone (primarily SiO2)
Metamorphic (low-grade)
Shale or Argillite
Shale (sedimentary) / Argillite (metamorphic)
Sedimentary or Metamorphic (low-grade)
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Sedimentary or Metamorphic (low grade)
Slate
Low-grade Metamorphic Rock
metamorphic
Slate
Foliated Metamorphic Rock
metamorphic
Slate
Slate (Foliated Metamorphic Rock)
metamorphic