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.
What Is Marble? It's good to know what marble is in order to understand how it behaves. It's a metamorphic stone, which is formed when sediment crystallizes under great heat or pressure to form hard rock. Marble is not the hardest of the these stones, however, making it porous and therefore susceptible to staining.