Definition
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Taconite is a low-grade iron ore which belongs to sedimentary rock and containing about 27% iron and 51% silica
History
Origin
-
Western Australia, Minnesota
Discoverer
Alexandre Brongniart and René Just Haüy
Newton Horace Winchell
Etymology
From Greek trakhus rough’ or trakhutēs roughness
From the name of Taconic Mountains in New England
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
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Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock