What is the crystal structure of calcite?
What is the crystal structure of calcite?
| Calcite | |
|---|---|
| Formula (repeating unit) | CaCO3 |
| Strunz classification | 5.AB.05 |
| Crystal system | Trigonal |
| Crystal class | Hexagonal scalenohedral (3m) H-M symbol: (3 2/m) |
Is calcite hexagonal or trigonal?
It has a formula unit composition of CaCO3. Its crystal system is trigonal and its habit varies more than any other mineral. Common habits are tabular and prismatic. Calcite has perfect rhombohedral cleavage.
How do you identify the mineral calcite?
By double refraction when light passes through calcite, it is split into two rays and is refracted twice. I would suggest to take a piece of paper and make a point with pencil, then place the calcite mineral on top of the point and see whether the point splits into two or not. If it does then it is calcite.
What are the physical properties of calcite?
| Physical Properties of Calcite | |
|---|---|
| Chemical Classification | Carbonate |
| Mohs Hardness | 3 |
| Specific Gravity | 2.7 |
| Diagnostic Properties | Rhombohedral cleavage, powdered form effervesces weakly in dilute HCl, curved crystal faces and frequent twinning |
What are the different types of calcite?
The three important crystal habits (distinctive shapes of the mineral) of calcite are: (1) prismatic (both short and long), (2) rhombohedral, and (3) scalenohedral. Twinning is very common and may be of secondary origin in crystalline limestones.
Is calcite a limestone?
Limestone is a rock made of calcite. Most limestone is grey, but all colours of limestone from white to black have been found.
How can you tell the difference between halite and calcite?
Calcite and halite are mineralogical names. The key difference between calcite and halite is that the calcite is the mineral form of calcium carbonate, whereas the halite is the mineral form of sodium chloride. Therefore, the chemical formula for calcite is CaCO3 and chemical formula of halite it is NaCl.
What is apatite for?
The primary use of apatite is as a source of phosphate in the manufacture of fertilizer and in other industrial uses. It is occasionally used as a gemstone.