1 Definition
1.1 Definition
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds
Nepheline Syenite is a holocrystalline plutonic rock resembling syenite but containing nepheline and lacking quartz
1.2 History
1.2.1 Origin
1.2.2 Discoverer
John Peter Salley
Unknown
1.3 Etymology
From the Old English term col, which has meant mineral of fossilized carbon since the 13th century
From origin of a Palaeozoic nepheline syenite from northern Shanxi Province, China
1.4 Class
Sedimentary Rocks
Igneous Rocks
1.4.1 Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock