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Facts About Quartz—Properties, Types, & Uses

A Botany graduate, Nithya Venkat enjoys researching and writing about topics that interest her.

Quartz Crystal

Quartz Crystal

Quartz is a mineral found in many rocks. It is one of the most common minerals found on earth.

Quartz was known since pre-historic times and appreciated for its beauty. "Krsitallos" was the ancient name recorded for quartz by Theophrastus in about 300-325 BCE.

This mineral is a crystalline form of silica. It can be found as a major component of igneous, metamorphic, and sedimentary rocks. It belongs to a group of minerals called silicates. Quartz can also be found in small grains as sand in the mountains, beaches, rivers, and deserts.

Quartz crystals dissolve in water at high temperatures and pressure. When this water seeps into rocks through cracks and fissures, it forms thin white seams and large veins of quartz that may extend to distances of over many kilometers.

Quartz Crystal Structure - Red color balls represent oxygen atoms and the white color balls represent silicon

Quartz Crystal Structure - Red color balls represent oxygen atoms and the white color balls represent silicon

Structure and Forms of Quartz

Structure of Quartz

Quartz is made of continuous chains of silicon and oxygen atoms arranged in the framework of tetrahedra.

Each silicon atom is surrounded by and connected to four oxygen atoms, and each oxygen atom is connected to two silicon atoms.

Crystal Structure of Quartz

Quartz crystals are hexagonal in shape and belong to the trigonal crystal system. The ideal trigonal crystal system is a six-sided prism that terminates with six-sided pyramids at each end. They frequently occur in twin form, where two crystals are joined at the base at 90 degrees.

The quartz crystals occur in nature as huge prismatic crystals, stubby crystals, or a pointed collection of prismatic and stubby crystals.

Forms of Quartz

Quartz occurs in two primary forms: the macrocrystalline and the microcrystalline, also known as the cryptocrystalline form.

Macrocrystal quartz is made of visible crystals. The rose quartz and the smoky quartz are examples of the macrocrystal quartz form.

Microcrystalline Quartz is made of tightly packed tiny crystals and crystallites that are visible only under a microscope. Agate, Jasper, Onyx are examples of the microcrystalline quartz form.

The piezoelectric effect was discovered in 1880 by two French physicists, brothers Pierre and Paul-Jacques Curie, in quartz crystals of Tourmaline and Rochelle salt.

Properties of Quartz

Pure quartz is colorless and transparent; it is also known as rock crystal or clear quartz. It can withstand chemical and mechanical weathering and does not break down easily.

Quartz is one of the hardest minerals on earth, measuring 7 on the Mohs Scale of Hardness.

Pure quartz is transparent and colorless, but impure quartz occurs in many colors such as white, gray, purple, yellow, brown, black, pink, green, and red.

Piezoelectric Nature

Quartz is a piezoelectric material. The word piezoelectric refers to the crystal's ability to convert mechanical stress into electricity and vice versa.

When mechanical stress is applied to a quartz crystal, the crystal converts the mechanical stress into electricity. When electricity is passed through a quartz crystal, it converts the electricity into a mechanical force that results in the crystal vibrating at a particular frequency.

Modern-day watches use the quartz crystal to keep accurate time. The quartz crystals have the ability to maintain an accurate frequency standard that helps to regulate the movement of quartz watches.

Piezoelectricity is used in ultrasound equipment, microphones, record players, spark lighters, and inkjet printers.

What is the Mohs scale of hardness?

Mohs hardness is a scale used to measure the resistance of a smooth surface to scratching or abrasion by a substance of known or defined hardness. This scale was devised by a German Mineralogist, Friedrich Mohs.

The Mohs scale ranges from 1 – 10 in which 1 represents a material very easily scratched, and 10 represents the hardest material highly resistant to scratching or abrasion.

Quartz measures 7 on the Mohs scale of hardness, and diamond, the hardest material, measures 10.

Types of Quartz Based on Color

Pure quartz is also called rock crystal. Pure rock crystal has a tiny percentage of impurities. It is colorless, transparent, or translucent.

Colored quartz crystals are valued for their color and beauty and are used as gemstones. Quartz colors are the result of traces of other minerals present in quartz crystals.

The following is a list of the different types of quartz by color.

Types of Quartz based on Color

TypeColorTransparency

Rock Crystal

Colorless

Clear

Amethyst

Purple

Transparent to Translucent

Rose Quartz

Pink

Transparent

Carnelian

Reddish Orange

Transparent to Nearly Opaque

Aventurine

Blue, Green, Yellow, Orange, Brown, Gray

Opaque

Agate

White, Blue, Red, Green, Yellow, Orange, Brown, Pink, Purple, Gray, Black, Multicolored

Translucent

Onyx

Black base with White Upper Layer

Opaque

Jasper

Red, Brown, Yellow

Opaque

Milky Quartz

White

Translucent to Opaque

Smoky Quartz

Light Grayish Brown to Deep Black

Transparent to Translucent

Tiger's Eye

Yellow, Brown, Multicolored

Opaque

Citrine

Yellow, Yellow-Brown, Orange, Dark Orange-Brown, Reddish-Brown

Transparent to Translucent

Prasiolite

Pale Gray Green to Deep Grass Green

Translucent

Tiger's Eye

Tiger's Eye

Agate

Agate

Uses of Quartz

Glass Making

Deposits of sand that have almost 100 % pure silica have been found in some locations. The sand from these deposits is used in the glassmaking industry to produce container glass, flat plate glass, specialty glass, and fiberglass.

Abrasive Agent

Quartz is a hard mineral and measures seven on the Moh’s scale and is an excellent abrasive substance. Quartz sand is used for sandblasting, as scouring cleansers for grinding and grit for sanding and sawing.

Flux for Smelting Metals

Quartz is mechanically and chemically strong, durable, and has a melting temperature that is higher than most metals. These properties make quartz an ideal mineral to make refractory bricks and flux in the smelting of metals.

Hydraulic Fracturing

Pure quartz is also known as the frac sand used in the petroleum industries for the process of hydraulic fracturing (fracking) that facilitates the flow of petroleum fluids such as oil, natural gas liquids, and natural gas from the rocks into the bore well.

Quartz sand with maximum purity is forced down oil and gas wells under high pressure. The high pressure fractures the rocks, and the sand slurry flows into the fracture. The quartz sand that is hard and durable keeps the fractures open without getting crushed and facilitates the flow of oil and natural gas into the bore well.

Quartz Crystals

The piezoelectric nature of quartz crystals has been utilized in manufacturing industries to make watches and equipment such as radios, televisions, electronic games, computers, cell phones, electronic meters, and GPS equipment.

Nowadays, quartz crystals are grown in laboratories based on the product for which it is being used. They can be grown in different shapes, sizes, and colors specifically needed for the manufacturing process.

As a Gemstone

Quartz is hard and durable and occurs in nature in a variety of colors. The colorful quartz crystals are used as gemstones to make jewelry.

To Summarize

Quartz is a mineral found in many rocks. It is one of the most common minerals found on earth. Quartz is made of continuous chains of silicon and oxygen atoms arranged in the framework of tetrahedra.

Quartz is one of the hardest minerals on earth, measuring 7 on the Mohs Scale of Hardness. This quality of quartz has made it an integral part of manufacturing industries. Colored quartz crystals are used as gemstones, and some of the crystals are said to have healing properties.

References

http://teachersinstitute.yale.edu/pubs/A5/vanwagner.html#c

http://geology.com/minerals/quartz.shtml

http://www.livescience.com/32509-why-is-quartz-used-in-watches.html

http://www.explainthatstuff.com/piezoelectricity.html

© 2017 Nithya Venkat

Comments

Nithya Venkat (author) from Dubai on June 04, 2018:

Frank thank you.

Frank Atanacio from Shelton on June 03, 2018:

what a wonderful informative hub Nithya.. it seems you did a great deal of research... fantastic

Nithya Venkat (author) from Dubai on September 14, 2017:

Audrey thank you, quartz is beautiful!

Nithya Venkat (author) from Dubai on September 14, 2017:

Jackie thank you for your visit and comment.

Audrey Howitt from California on September 12, 2017:

Such a beautiful hub--I love quartz--I have always been drawn to it--

Jackie Lynnley from the beautiful south on September 06, 2017:

Had no idea about most of this. Very well done. Love to learn, especially of something so beautiful.

Nithya Venkat (author) from Dubai on June 28, 2017:

ChitrangadaSharan thank you for your appreciation ad comment.

Chitrangada Sharan from New Delhi, India on June 25, 2017:

Excellent, well researched and very informative article about Quartz!

There is so much to learn here. I do have Amethyst, Onyx, Tiger's eye as gemstone/ jewellery at home. But I didn't know so much about Quartz , it's uses and other varieties.

As always you have put in lot of effort in gathering the information and very useful for readers.

Thanks for sharing!

Nithya Venkat (author) from Dubai on June 17, 2017:

rajan jolly thank you for your visit and comment.

Rajan Singh Jolly from From Mumbai, presently in Jalandhar, INDIA. on June 16, 2017:

Quartz is not only very useful and beautiful as well. Very informative article. Thanks for sharing.

Nithya Venkat (author) from Dubai on June 16, 2017:

srsddn thank you and am glad you got to know more about quartz through this hub.

srsddn from Dehra Dun, India on June 15, 2017:

Nithya, something totally new. There is so much to learn and thanks for sharing these details about one of the hardest materials on the earth.

Nithya Venkat (author) from Dubai on May 29, 2017:

vocalcoach rose quartz is beautiful! Thank you for stopping by.

Nithya Venkat (author) from Dubai on May 29, 2017:

always exploring thank you and am happy you found this interesting.

Ruby Jean Richert from Southern Illinois on May 26, 2017:

Wow, you put a lot of research into this article. I knew very little about quartz. Interesting read....

Audrey Hunt from Idyllwild Ca. on May 24, 2017:

Informative and interesting. I love gemstones. One of my favorites is rose quartz which sits on my desk.

Nithya Venkat (author) from Dubai on May 20, 2017:

The rose quartz light must be amazing! Thank you for the visit and comment.

Marc Hubs from United Kingdom on May 18, 2017:

Excellent article and information, thank you. I'm wondering about your opinion of Orgonite? It's supposedly used for healing and protection against EMF. It's basically crystals and metals encased in a fibreglass resin which shrinks in order to squeeze the crystals and induce piezoelectricity.

According to research, the non-organic materials (fibreglass) absorb life-force energy and deflect it in all directions whereas the organic materials (metals) deflect back in the direction from which it came (back towards to the fibreglass) and the crystals transmute the energy into a healthy charge.

In other words, it allegedly absorbs and cleanses etheric life-force energy. I'm just wondering what you make of this? It's based on the research of Wilhelm Reich which is quite extensive. Do you think inducing piezoelectricity in such a way would actually increase the healing capacity of crystals, or do you think it would do the opposite?

Nell Rose from England on May 18, 2017:

I have a beautiful rose quartz light that I have had for over 20 years, it just packed up so its now on my window ledge catching the light! what a great hub! so interesting!

Nithya Venkat (author) from Dubai on May 17, 2017:

Demas W Jasper The Arkansas quartz belt is a major producer of gemstones and decorative rock crystal and it is the source of "lascas" that is the feed material used to make synthetic quartz. Rock crystals are also got from quartz veins in sandstone and shales of the Ouachita mountains where the quartz belt is about 240 km long and 24 km wide. Deposits of quartz can also be found in California and New York.

Nithya Venkat (author) from Dubai on May 17, 2017:

billybuc thank you and am happy you find something new to learn.

Nithya Venkat (author) from Dubai on May 17, 2017:

FlourishAnyway thank you; I love all things about nature and rocks are one of the many things that I admire.

Nithya Venkat (author) from Dubai on May 17, 2017:

Peggy W thank you, quartz does not break down easily.

Nithya Venkat (author) from Dubai on May 17, 2017:

AliciaC thank you for your visit, quartz gemstones are so beautiful.

Nithya Venkat (author) from Dubai on May 17, 2017:

Venkatachari M glad you found this article interesting and informative, thank you for the visit.

Venkatachari M from Hyderabad, India on May 17, 2017:

Very interesting information about Quartz. I am new to this subject and learned some interesting facts here. Thanks for sharing it.

Linda Crampton from British Columbia, Canada on May 16, 2017:

Quartz can be beautiful. I love your photos. Thank you for sharing so many facts about the mineral.

Peggy Woods from Houston, Texas on May 16, 2017:

It was very interesting learning more about quartz. I have some that I purchased decorating my garden amidst other rocks I have collected. Nice to know how hard it is. It will stand up to all kinds of weather.

FlourishAnyway from USA on May 16, 2017:

So well researched. I love amethysts and tiger's eye. What prompts your interests in rocks?

Demas W Jasper from Today's America and The World Beyond on May 16, 2017:

I wonder, are there "belts" of quartz in the USA, or is it widespread with no particular locus?

Bill Holland from Olympia, WA on May 16, 2017:

I like these articles of yours. I always learn something new. Thank you!