Definition
Teschenite is coarse- to fine-grained, dark-coloured intrusive igneous rock that usually occurs in sills, dikes and irregular masses and is always altered to some extent
Rapakivi Granite is a hornblende-biotite Granite containing large rounded crystals of orthoclase which are mantled with oligoclase
History
Origin
Scotland
Finland, Europe
Discoverer
Unknown
Jakob Sederholm
Etymology
From its occurrence near Teschen. now known as Cieszyn, Pol., Scotland
From Finnish Rapakivi which stands for crumbly rock
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Plutonic
Plutonic
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock