Definition
Granite is a very hard, granular, crystalline igneous rock which consists mainly of quartz, mica, and feldspar and is often used as building stone
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
History
Origin
-
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Discoverer
Alexander von Humboldt
Alexandre Brongniart and René Just Haüy
Etymology
From Italian granito, which means grained rock, from grano grain, and from Latin granum
From Greek trakhus rough’ or trakhutēs roughness
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Plutonic
Volcanic
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock