Metamorphic rocks - Slate 

Page / - last modified by Roelof Zwaan on 2021/09/30 15:18 

Slate 
last modified by Roelof Zwaan
on 2021/09/30 15:18

Table of Contents

Slate is a fine-grained foliated metamorphic rock. This rock originates from shale and transformed from shale into slate. When metamorphism continues it forms phyllite, then schist and finally into gneiss.
Characteristics
Slate has a dominant foliation and due to this fact slate falls apart in thin platy pieces. Slate originate from low-grade regional metamorphism at a former sedimentary basin involved in convergent plate boundaries, which means it forms under horizontal forces and minor heating. Slate can be distinguished from phyllite by its grain size. The grain size of slate is much smaller than that from phyllite.
Composition
Slate is mainly composed of quartz and some metamorphosed clay minerals. Most slates are grey in color and range from light to dark. The minerals in slate form at right angles to the compressive forces of the convergent plate boundary to yield a vertical foliation that usually crosses the bedding planes that existed in the shale.
References
•	NEN-EN-ISO 14688-1:2019
•	https://geology.com/
Slate

Type	Metamorphic rock	
Texture	Platy	
Clasts	Very fine grained	
Hardness	Medium hard	
Color	Grey to dark grey	
Minerals	Quartz and mica minerals	
Touch	Smooth	
Image	Slate	
Contents
•	Characteristics
•	Composition
•	References
•	Slate