Definition
Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism
History
Origin
-
England
Discoverer
R. J. Hauy
Abraham Gottlob Werner
Etymology
From Greek pegma, pegmat which means- thing joined together + -ite
From Old French esclate, from esclat (French éclat)
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Plutonic
-
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock