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
Marble is a non-foliated metamorphic rock which is composed of recrystallized carbonate which is formed when limestone is exposed to high temperatures and pressures over a long time
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 the Greek marmaros, shining stone and also from the English word marmoreal meaning marble-like
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
Medium Grained Rock, Opaque Rock