What is you rock?

I am a sedimentary rock called limestone.

• Composition: I am primarily composed of calcium carbonate (CaCO3) in the form of the mineral calcite. I may also contain small amounts of other minerals like quartz, clay minerals, and dolomite.
• Formation: I form in various ways, but the most common is through the accumulation of shell, coral, algae, and fecal debris. These sediments are then compressed and cemented together over millions of years in a process called lithification. I can also precipitate directly from seawater.
• Environment: I am typically found in marine environments. Such environments have warm, shallow waters, such as tropical reefs and continental shelves.
• Uses: I have many uses, including: production of cement, building stone, and agricultural lime (for neutralizing acidic soils). I am also used in the production of glass and as a flux in metallurgy.
• Identification: I am generally light-colored (white, gray, or tan), relatively soft (can be scratched with a knife), and will fizz when acid (like hydrochloric acid) is applied.