Building materials — chemical classification of marble Chemically, marble belongs to which rock class?

Introduction / Context:
Construction materials are often classified both by origin and by dominant chemistry. Marble is widely used for cladding, flooring, and sculptures. Identifying its chemical family supports decisions on durability, weathering, and compatibility with mortars and cleaning agents.

Given Data / Assumptions:

• Marble forms by metamorphism of limestone.
• Limestone is primarily calcium carbonate (CaCO3).
• Chemical families: calcareous (lime-rich), siliceous (silica-rich), and argillaceous (clay-rich).

Concept / Approach:
Although marble is a metamorphic rock by origin, its chemistry remains dominated by calcium carbonate, making it calcareous. Chemical classification addresses susceptibility to acids and salts—key for maintenance and restoration.

Step-by-Step Solution:
Recognize marble's parent rock: limestone.Identify main constituent: CaCO3 (calcite), a lime-rich material.Select the chemical class: calcareous.

Verification / Alternative check:
Effervescence when a drop of dilute acid is applied confirms calcareous nature due to CO2 release from CaCO3.

Why Other Options Are Wrong:
Metamorphic describes genesis, not chemistry for this question. Argillaceous implies clay minerals dominate. Siliceous implies silica-rich minerals (e.g., quartz, sandstone), which is not the case.

Common Pitfalls:
Confusing geological classification (metamorphic) with chemical classification (calcareous). Field tests often blur the distinction unless the question is read carefully.

Final Answer:
Calcareous rock