Calcite vs Quartz: A Detailed Comparison

Calcite and Quartz are minerals commonly found in rocks around the world. Both minerals occur in various colors, including purple, white, brown, gray, and colorless, which causes them to look similar at times.

If you are looking for a comparison of Calcite vs Quartz, whether in terms of their shapes and sizes or their properties and uses; we have a complete detailed comparison between them for better understanding.

Calcite vs Quartz: Meaning

Meaning of Calcite

Calcite is a carbonate mineral. This mineral is also the most stable calcium carbonate polymorph. Additionally, Aragonite and vaterite are two more polymorphs of calcium carbonate. Aragonite can change into Calcite. It can occur on days or at temperatures over 300 °C. This mineral is available in several forms.

Calcite comes in over 800 different forms. The most prevalent of these shapes are scalenohedra and rhombohedra. Moreover, it has three descriptive hardness levels on the Mohs Mineral Hardness Scale.

A calcite crystal displays an optical property called birefringence. This property is also known as birefringence. Therefore, the objects seen through the crystal appear double. Since it is a carbonate mineral, it can dissolve in acids. This crystal is also helpful for many purposes, including jewelry making and carving.

Read more about Meaning of Calcite and its Uses.

Meaning of Quartz

The term derives from the German word ‘Quartz.’ It is part of the triangular crystal system. It is present in open cast mines. Quartz refers to a challenging and crystalline mineral. Moreover, this mineral consists of silica or silicon dioxide.

The general chemical formula given is SiO2. The second most abundant mineral found in Quartz. Quartz can be either a high-temperature Quartz or Beta (β)- Quartz or a Standard Quartz or Alpha (α)- Quartz.

Quartz comes in many varieties. Most of these are also semi-precious stones. People widely use them for jewelry making and carving. Clear Quartz, Amethyst, Citrine, Rose quartz, and Smoky Quartz are some of the popular Quartz available. These are also healing stones. Several people use them to achieve calmness, love, peace, and other things.

Calcite vs Quartz: Mineral Composition

Hardness of Calcite vs Quartz

Mineral hardness is an important attribute that scientists use to identify samples. Quartz is four times as hard as Calcite. A quartz specimen may scratch a calcite specimen, while Calcite cannot scratch Quartz. If you have a sample of either, try plotting one sample against the other to see how the hardness differs.

The knife’s blade has a hardness rating between Calcite and Quartz. The blade will scratch a calcite crystal but not a quartz crystal.

Crystal shape of Calcite vs Quartz

Quartz and calcite crystals have distinctly different crystal shapes. The most common form of Calcite is a rhombus, but it can also form prismatic crystals, scalenohedrons, and other less common shapes and combinations. The most common form of Quartz is a hexagonal prism terminated by six-sided pyramids at both ends of the crystal. Many quartz crystals may not exhibit a perfect crystal shape or appear to have a three-sided pyramid at the tip.

Division and Fracture of Calcite vs Quartz

Calcite exhibits rhombic cleavage, which means it fractures along three planes of weakness, forming a rhombic shape for the crystal. Quartz does not have strong cleavage but can break through the crystal, leaving a rough surface on the broken crystal. Quartz fractures are defined as conchoidal when the fracture surface shows a swirl pattern on the stone.

Calcite vs Quartz: Chemical Composition

Calcite is a calcium carbonate mineral, whereas Quartz is a silicon dioxide crystal. You can’t tell the difference in mineral composition just by looking at it, but you can test it to check if the crystal you have is Calcite.

Calcium carbonate interacts with an acid to generate bubbles on the crystal’s surface. Test your sample by drizzling diluted hydrochloric acid, lemon juice, or vinegar on it and watching for bubbles. Quartz is unaffected by dilute acid.

Calcite vs Quartz: Appearances

Quartz and Calcite have a lot in common, but there are also many differences between them. Quartz is silicon dioxide, while Calcite is calcium carbonate. Oxygen and silicon are also present in Quartz.

Calcite vs Quartz: Physical Properties

Calcite Physical Properties

Calcite is classified as carbonate and is usually white. However, it can also be colorless, red, gray, blue, green, yellow, orange, or brown. It forms a white streak and has a glassy luster. It can be transparent or translucent. It is relatively soft, ranking only 3.0 on the Mohs hardness scale.

Quartz Physical Properties

Depending on the ingredients it is mixed with, Quartz can appear in almost any color. The most common colors include clear, white, gray, yellow, pink, purple, green, and red.

Because it is more challenging than a streak plate, it has a colorless streak and a vitreous luster. It can be both transparent and translucent. It ranks at 7.0 on Moh’s hardness scale, making it very tough and pliable.

Calcite vs Quartz: Color and Shape

Calcite comes in colorless, white, light orange, yellow, blue, red, pink, brown, black, green, and grey crystals. On the other hand, Quartz comes in white, hazy, purple, pink, grey, brown, and black varieties.

Calcite has a sheen that ranges from vitreous to resinous to matte, whereas Quartz has a luster that ranges from vitreous to vitreous. Calcite and Quartz are both translucent and transparent. Cryptocrystalline, on the other hand, ranges from transparent to opaque.

Calcite is available in rhombus, scalenohedron, hexagonal, and pinacoid shapes. The majority of calcite minerals are trigonal or pseudo-hexagonal in shape. Quartz is a hexagonal prism with enormous spherical, botryoidal, and stalactite forms.

In the case of Calcite, cleavage is perfect in three directions, whereas in Quartz, cleavage is weak in three directions.

Calcite vs Quartz: Presence in Nature

Calcite is found in many sedimentary rocks such as limestone, while Quartz is more prevalent in igneous rocks such as granite and basalt.

Calcite is also the main component of stalagmite and stalactite formations found in caves and shells of marine organisms such as sponges and oysters. Quartz is not associated with living things but is also a component of quartzite, gneiss, and other metamorphic rocks formed under high pressure and temperature.

Calcite vs Quartz: Uses

Uses of Calcite

Calcite is used in the construction industry to make cement and mortar. It is also used in the chemical and pharmaceutical industries as an acid neutralizer and saves rivers, lakes, and soils with low pH levels.

Calcite has several applications, one of which is the production of acid-neutralizing medicines. Calcite has been crushed and used in agriculture for generations to help neutralize the acid in soils.

The crushed Calcite helped neutralize this effect in the water. High purity marble is a source of calcium carbonate, and limestone is used frequently in medicine for human consumption. When mixed with flavor and coloring, you can use it as easy-to-chew tablets that help reduce stomach acid. However, it is also often used in other medicines to help treat digestive issues and many other physical ailments. Besides being used in medicine, Calcite is also widely used for monuments, sculptures, and buildings in Marble.

Uses of Quartz

Quartz is an essential mineral, an industrial abrasive in the glassmaking process, and a gemstone in jewelry. In terms of usefulness, Quartz is one of the most widely used minerals globally. As a gemstone, it is famous for use in jewelry, although it also has a variety of industrial uses.

Quartz is widely used in glassmaking and has created flat glass, fiberglass, container glass, and specialty glasses. Its hardness also makes it popular for use as an abrasive, as it can easily irritate softer materials. It makes it familiar in sandblasting, grinding, and scouring operations.

Other uses include rubbers, paints, sealants, and fillers in golf courses, sandboxes, baseball fields, and softball courts.

Calcite and Carbon

Carbon dioxide is a greenhouse gas that helps trap and retain heat near the planet’s surface.

As a result, it contributes to climate change. However, processes that make limestone remove this gas from the atmosphere, and you can store it in the stone for a long time.

Because this process has been occurring for millions of years, there are incredible volumes of this gas stored in limestone deposits on Earth. This cycle helps to show how intertwined the processes of the planet are.

Quartz Crystals

Besides their use when ground, solid quartz crystals also have unique properties that make them extremely useful.

For example, quartz crystals are capable of vibrating precisely along with frequencies. These crystal oscillators were first developed in the 1920s and later during World War II.

Today they are found everywhere, from watches and clocks to televisions, cell phones, GPS equipment, and computers.

Conclusion

Both Quartz and Calcite are common minerals. The first is silicon dioxide, and the second is a carbonate mineral. In comparison, Quartz is tougher than Calcite.

Both minerals can be present in a variety of forms. The look of the minerals is also very diverse.

Quartz comes in various hues, including blue, yellow, and purple. Calcite, on the other hand, is invariably white or opaque. Contaminants can alter the color of the calcite mineral. There are a variety of applications for these minerals all over the world.