Why Chalk and Limestone Are Inorganic Treasures

Chalk and limestone are mainly made of calcium carbonate (CaCO₃), a key inorganic compound.
Chalk formed from the microscopic shells of ancient marine organisms, compacted over millions of years.
Limestone often preserves fossils, acting as a natural archive of prehistoric seas.
Both dissolve slowly in acids, showing the classic carbonate reaction that fizzes with bubbles of CO₂.
Chalk was once the writing tool of choice for classrooms worldwide.
Limestone is a cornerstone of construction, used in cement, concrete, and building blocks.
The white cliffs of Dover in England are a dramatic example of chalk geology on display.
Limestone landscapes, or karst terrain, create caves, sinkholes, and dramatic rock formations.
Heated limestone transforms into quicklime, an important industrial chemical.
From ancient temples to modern classrooms, chalk and limestone are everyday gifts of inorganic chemistry.