1 Definition
1.1 Definition
Litchfieldite is a rare igneous rock which is coarse-grained, foliated and a variety of nepheline syenite, sometimes also called as nepheline syenite gneiss or gneissic nepeheline syenite
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds
1.2 History
1.2.1 Origin
1.2.2 Discoverer
1.3 Etymology
From its occurrence at Litchfield, Maine, USA
From the Old English term col, which has meant mineral of fossilized carbon since the 13th century
1.4 Class
Igneous Rocks
Sedimentary Rocks
1.4.1 Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock