The term calcareous can be applied to a sediment, sedimentary rock, or soil type which is formed from, or contains a high proportion of, calcium carbonate in the form of calcite or aragonite.

**Calcareous Rock:**

Marble is chemically known as a calcareous rock. This means that it is composed primarily of calcium carbonate (CaCO3). Calcareous rocks are formed from the accumulation of the remains of marine organisms such as coral, shells, and other organic materials that contain calcium carbonate.

**Formation of Marble:**

Marble is formed through the process of metamorphism, which involves the transformation of pre-existing rocks under high pressure and temperature conditions. The original rock, known as the parent rock, can be limestone or dolomite. These rocks are composed primarily of calcium carbonate.

During metamorphism, the parent rock is subjected to intense heat and pressure, causing the minerals within it to recrystallize and form new structures. The calcium carbonate in the parent rock undergoes a process of recrystallization, resulting in the formation of large interlocking calcite crystals. This gives marble its characteristic texture and appearance.

**Characteristics of Marble:**

Marble is known for its distinctive veining patterns and a wide range of colors, including white, gray, pink, green, and black. It has a smooth and lustrous surface that can be polished to a high shine. Marble is relatively soft compared to other stones and can be easily carved and shaped, making it a popular choice for sculptures and architectural applications.

Marble is also valued for its durability and resistance to heat and weathering. It is commonly used in construction for flooring, countertops, wall cladding, and decorative elements. The unique patterns and colors of marble make it a highly sought-after material for interior design and decorative purposes.

**Applications of Marble:**

Marble has been used in various architectural and artistic applications throughout history. It has been used to create iconic structures such as the Taj Mahal in India and the Parthenon in Greece. In modern times, marble is still widely used in luxury homes, hotels, and public buildings for its aesthetic appeal and durability.

In conclusion, marble is known as a calcareous rock because it is composed primarily of calcium carbonate. It is formed through the process of metamorphism, which involves the recrystallization of calcium carbonate minerals in pre-existing limestone or dolomite rocks. Marble exhibits distinct veining patterns and a wide range of colors, making it a popular choice for architectural and decorative applications.

Marble contains calcium. High content of calcium refers to calcareous materials like lime,chalk,marble etc.