Chlorite Green Slate
Chlorite green slate is a slate colored sage to olive green by chlorite, a green iron- and magnesium-rich sheet silicate. It splits into flat plates like other slates and is often derived from muddy sediments or volcanic ash rich in iron and magnesium.
Chlorite green slate is a slate colored sage to olive green by chlorite, a green iron- and magnesium-rich sheet silicate. It splits into flat plates like other slates and is often derived from muddy sediments or volcanic ash rich in iron and magnesium.
🪨 Geology Guide Specimen: Open Chlorite Green Slate in the CRV Science Rock & Mineral ID Guide to log the specimen, compare it with the other 6 subgroups of Metamorphic, and test your eye in LithoClade.
Chlorite: What Makes the Green?
Chlorite is a group of hydrous sheet silicates containing iron, magnesium and aluminum. It grows in low-grade metamorphism when clays and volcanic debris recrystallize, and its green color and platy form give the rock its character. Sericite, albite and quartz are the other main components.
Greenschist Facies: What Does Chlorite Mark?
Chlorite is so typical of this range of temperature and pressure, roughly 300 to 500 degrees Celsius, that geologists call the whole range the greenschist facies. Chlorite-bearing slates therefore mark the entry to that zone, which grades toward chlorite actinolite schist with rising grade.
Uses: Where Is Green Slate Quarried?
Chlorite Green Slate at a Glance
| Property | Value |
|---|---|
| Type / variety | Chlorite-Bearing Low-Grade Cleaved Metapelite |
| Composition | Microscopic Chlorite + Sericite White Mica + Albite + Quartz |
| Geology Guide group | Metamorphic Rocks (Foliated, Granoblastic & High-P) |
| Rock Classification | Low-Grade Foliated (Slate & Phyllite) |
| Mohs hardness | Mohs 3–4 |
| Texture / habit | Planar tectonic cleavage with smooth matte-to-faintly-satiny surfaces |
| Density | 2.75–2.84 g/cm³ |
| Lustre and cleavage | Grayish-sage to olive-green planar splitting plates |
| Geological setting | Low-grade regional compression of iron/magnesium-rich muds and volcanic ash |
| Diagnostic feature (Geology Guide) | Sage- to olive-green rock that splits cleanly into smooth, flat architectural shingles; its green hue comes from microscopic iron-magnesium sheet silicates aligned perpendicular to tectonic compression. |
| Color source | Chlorite |
| Facies | Greenschist |
See Also
- Slate — the broader rock family
- Chlorite Actinolite Schist — the higher-grade green rock
- Magnesium — an element in chlorite