Calcite
* Chemical Composition: Calcium carbonate (CaCO₃)
* Mineral: It's a specific mineral, meaning it has a defined chemical composition and crystal structure.
* Appearance: Typically clear, white, or slightly yellowish, but can come in other colors depending on impurities. Can be found in various forms, including crystals, grains, and massive forms.
* Hardness: 3 on the Mohs Hardness Scale (can be scratched by a copper coin)
Limestone
* Rock Type: It's a sedimentary rock primarily composed of calcite (CaCO₃), but can also contain other minerals like clay and quartz.
* Formation: Formed by the accumulation of the remains of marine organisms like shells, coral, and algae over millions of years.
* Appearance: Often gray, tan, or white, but can be other colors. Can be found in various textures, from coarse-grained to fine-grained.
* Uses: Building material, cement production, and a source of calcium.
In short:
* Calcite is a single mineral, while limestone is a rock.
* Limestone is made up of calcite, along with other minerals.
Think of it like this: Calcite is like the ingredient "sugar", and limestone is like a "cake" that uses sugar as a primary ingredient.
