All About Calcite – Uses, Properties, Color, and Worth
Calcite is defined as a calcium carbonate mineral. It is so common it is found all over the world. Calcite crystals have been found in over 800 different forms and is a major component in limestone and marble.
Do not think of calcite as a type of rock, but a major mineral component in sedimentary rocks like limestone, or metamorphic rocks like marble. We cannot forget Igneous types of rocks, as calcite can be found in them as well.
Calcite can be dissolved by ground water or precipitated by ground water. This all depends on factors like temperature, pH, and dissolved ion concentrations. Being able to dissolve or be precipitated, and then the ability to re-precipitate, recrystallize, and even dehydrate, makes calcite a type of carbon dioxide storage process for the earth. In quick, calcite can go to our atmosphere and then back to solid form.
It takes a long time for carbon dioxide in our atmosphere to collect and form as calcite. This collection ends up being stored in rocks like limestone. Through the uses of industry, we end up releasing tons of carbon dioxide into our atmosphere from calcite usage.
This kind of carbon dioxide release is not looked at as harshly though, as the burning of fossil fuels seems to be the focus when it comes to carbon dioxide emissions into our atmosphere.
Calcite Properties
 | |
| Calcite Mohs Scale Hardness | 3 |
| Specific Gravity | 2.71 |
| Calcite Streak | White |
| Fracture | Sub-Conchoidal |
| Calcite Luster | Vitreous to pearly to dull |
| Crystal System | Trigonal |
| Calcite Cleavage | Perfect. On three directions to form the rhombohedral. |
| Calcite Chemical Formula | CaCO3 |
Calcite has a hardness of 3 on the Mohs scale of hardness. The Mohs scale of harness has calcite as its very example of a hardness at “3”. It is often referred to as the hardness of calcite.
As an example of calcite hardness, calcite cannot scratch glass. Glass will have a hardness of 5.5 to 7 on the Mohs scale of hardness. With calcite being a 3, glass will be too hard to receive a scratch from calcite.
Calcite Color
Calcite color can be colorless, white, gray, yellow, red, blue, orange, and green. Calcite has the ability to take on other colors such as the example of a reddish hue in crystals due to the presence of iron or other elements available when it was formed…
A lot of samples or specimens of calcite do not really generate a lot of interest for many people unless it is in more of a larger crystal form. The crystals that do have the more eye catching hues of red, blue, orange, and green, can have such a rich color with it that it would be difficult to pass up an opportunity to own one of these calcite specimens.
Honey calcite is a colorful form of a calcium carbonate mineral. They call it honey calcite because it’s color is a nice yellowish brownish honey color. This form of calcite is very collectable by rock and mineral enthusiasts.
What is Calcite used for?
Calcite uses will be primarily in construction materials to help create buildings, roads, walls, and other good building materials. The uses of calcite have also found their way into the building of cosmetic type structures. It is good for applications such as benches, statues, headstones, and other decorative structures…
Most of the building items mentioned are due to calcite being mixed into cements and mixtures to help create the concrete and cement. There are other applications as well when it comes to calcite.
Calcite can be found in medicines such as antacids, it can be added to farm animal feeds, and it will be a primary ingredient in whitening paints.
Some people believe that calcite has some healing properties that are good for cleansing the spirit and calming your spiritual connection while carrying it in crystal form. Though such beliefs can be considered far-fetched, it is good to note that calcite is in fact used in some medical applications, as mentioned earlier.
What is Calcite worth?
Calcite worth and value will be quite small as it is literately all over the world. Its worth will be in regards to the many applications for it that affect our lives. This is where the worth of calcite is quite invaluable, even though it will remain relatively cheap…
If you are looking for calcite as a specimen, the price will range based on size, shape, and color. For the most part though, you will not have to spend much money to get some samples of this mineral even in some of the nicer looking colors.
Calcite Florescence
Calcite florescence is common with this mineral. Using long wave or short wave UV light you can bring out some very interesting florescence colors of white, green, blue, red, orange, and pink.
This is one of the reasons many like to obtain a nice specimen of calcite. To be able to see the florescence effect on calcite you will need to obtain a long wave or short wave UV lamp. There are a lot of UV flashlights available for purchase, however most of those are long wave.
If you have ever been to a rock and mineral show, you might notice a walk in booth that appears to be dark inside. This booth will contain a display that allows you to switch on or off a regular light source with an Ultra Violet light source.
Along with calcite, you can see other examples like Willemite, Dolomite, Adamite, Scheelite, Agate, Tremolite, Fluorite, Rhyolite, and many other rocks and minerals express fluorescing behavior. Ironically enough, many rocks and minerals will have calcite in it, which will actually be the calcite fluorescing.
Where is Calcite Found?
Calcite is found all over the world in the earths crust. Calcite can be found in sedimentary, metamorphic, and igneous rocks. Calcite can often be found in hydrothermal environments and make up some of the stalactites and stalagmites we see in caves.
Calcite deposits can occur in many different rocks and even find their way in and around other minerals. It will seep into and fill cracks and crevices of many host rocks to form many of the metamorphic, sedimentary, and igneous rocks we see today.
One great example is with lapis lazuli and its great contrast between blue and white within the rock. Often the white impurities that can manifest itself within lapis lazuli will be higher concentrations of calcite.
Calcite vs Quartz
Calcite and quartz may look the same in some regard to appearance but they are very different. Calcite is a calcium carbonate mineral while quartz is a silicate mineral with a chemical formula of SiO2. Quartz has a hardness of 7 on the Mohs scale of hardness while Calcite is much softer at a 3.
