metamorphic
Banded Slate (Sedimentary Pebble)
Slate (Metamorphosed Shale or Mudstone)
Hardness: 2.5-4 (Mohs); Color: Dark grey to black with light grey/white mineral bands; Luster: Dull to slightly silky; Crystal Structure: Microcrystalline with slaty cleavage; Specific Gravity: 2.7-2.8
- Hardness
- 2
- Color
- Dark grey to black with light grey/white mineral bands
- Luster
- Dull to slightly silky
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 2.5-4 (Mohs); Color: Dark grey to black with light grey/white mineral bands; Luster: Dull to slightly silky; Crystal Structure: Microcrystalline with slaty cleavage; Specific Gravity: 2.7-2.8
Formation & geological history
Formed through the low-grade regional metamorphism of shale or mudstone. The bands represent original sedimentary layers (bedding) or mineral segregations during pressure. It can date from various geological periods, often Paleozoic.
Uses & applications
Roofing tiles, billiard table tops, blackboards, and decorative landscaping. Smooth pebbles are often used in stress relief (worry stones) or garden ornaments.
Geological facts
Slate naturally splits into thin, flat sheets due to its foliation. It is often used in historic structures because of its low water absorption and resistance to freezing.
Field identification & locations
Identify by its fine-grained texture, distinct layering (bands), and ability to split into flat planes. Commonly found in riverbeds or beaches near ancient mountain ranges and metamorphic belts.
More like this
