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
A hydration and metamorphic transformation of ultramafic rock from the Earth's mantle is called as serpentinization, a group of minerals is formed by serpentinization compose rock 'serpentinite'.
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 English word serpentinization.
1.4 Class
Sedimentary Rocks
Metamorphic Rocks
1.4.1 Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
1.5 Family
1.5.1 Group
Not Applicable
Not Applicable
1.6 Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock