Definition
Taconite is a low-grade iron ore which belongs to sedimentary rock and containing about 27% iron and 51% silica
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
History
Origin
Western Australia, Minnesota
Germany
Discoverer
Newton Horace Winchell
Van Tooren
Etymology
From the name of Taconic Mountains in New England
From Greek tephra, ashes from Indo-European base, to burn
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
-
Volcanic
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock