Short answers, pulled from the story.
Marble is a metamorphic rock made of carbonate minerals, most commonly calcite or dolomite, that recrystallized under heat and pressure. In geology it refers to metamorphosed limestone or dolomite, in which the original sedimentary grains form an interlocking mosaic of carbonate crystals.
White marble has been prized for sculpture since classical times because of its softness, relative isotropy and homogeneity, and resistance to shattering. The low index of refraction of calcite lets light penetrate 12.7 to 38 millimeters into the stone before scattering, giving sculptures a lifelike waxy luster.
Four countries account for almost half of world production of marble and decorative stone. China leads at 34% and Italy at 19%, followed by India at 16% and Spain at 13%. In 2018 Turkey was the world leader in marble export with a 42% share.
Acids react with the calcium carbonate in marble, producing carbonic acid that decomposes into carbon dioxide and water, along with soluble salts. Outdoor marble statues and structures are damaged by acid rain through carbonation, sulfation, or the buildup of a black crust, so vinegar and acidic cleaners should be avoided.
The swirls and veins of colored marble, sometimes called striations, come from mineral impurities such as clay, silt, sand, iron oxides, or chert present in the original limestone. Green coloration often comes from serpentine formed from magnesium-rich limestone or dolomite with silica impurities.
Cutting marble produces elevated particulate air pollution that can impair lung function or cause lung disease such as silicosis, along with skin and eye problems. In the United States, OSHA sets a permissible exposure limit of 15 mg/m3 total and 5 mg/m3 respiratory over an 8-hour workday.
Marble is soft and porous, easily scratched and stained, and corroded by alcohol or acidic liquids. A marble floor can be vacuumed to remove grit and dust, cleaned with a steam cleaner, and washed with a mild, pH-neutral, non-abrasive soap.