Black tea is made from the leaves of a bush called Camellia sinensis. A process called oxidation turns the leaves from green to a dark brownish-black color. Oxidation means the leaves are exposed to moist, oxygen-rich air.
Marble is a non-foliated metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite. Geologists use the term marble to refer to metamorphosed limestone; however, stonemasons use the term more broadly to encompass unmetamorphosed limestone.Marble is commonly used for sculpture and as a building material.eologists use the term marble to refer to metamorphosed limestone; however, stonemasons use the term more broadly to encompass unmetamorphosed limestone.
Marble is a type of metamorphic rock. Marble usually originates as limestone or dolomite. Calcite, dolomite crystals, and aragonite are the key components of marble. Impurities are what gives marble its color. Marble is typically found among other metamorphic rock such as gneiss and mica schist.