Quartz is one of the most abundant minerals on the planet and is quite an affordable gemstone. Diamond, on the other hand, is a rare mineral that is quite expensive. However, there are many differences besides their abundance and price, which we will discuss in this article.

We will look at their various properties, such as chemical composition, hardness, clarity, etc. Then, we will learn how to take care of them. Finally, we will discuss how to differentiate quartz from diamonds.

Read: Lapis Lazuli vs Sodalite (Full Comparison)

What is Quartz?

Quartz is a mineral composed of silicon and oxygen atoms arranged in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. It is one of the most abundant minerals on Earth and occurs in many different forms, including clear, smoky, rose, and amethyst.

Quartz is often used as a semi-precious gemstone in jewelry making and is also used in a variety of industrial applications, such as electronics, glassmaking, and construction. It is found in many different countries around the world, including Brazil, Madagascar, and the United States.

What is a Diamond?

A diamond is a precious gemstone that is composed of carbon atoms arranged in a crystal lattice structure. It is the hardest naturally occurring substance on Earth and is highly valued for its beauty and rarity.

Diamonds are typically transparent or translucent and range in color from colorless to yellow, brown, or even pink, blue, or green. They are formed deep within the Earth’s mantle under high pressure and temperature conditions and are brought to the surface through volcanic eruptions.

Diamonds are used primarily in jewelry making, but they also have industrial applications in cutting, drilling, and polishing tools. The value of a diamond is determined by its carat weight, clarity, color, and cut.

Similarities Between Quartz and Diamond

Although quartz and diamond differ in many ways, they also have some differences:

• In terms of opacity, both of them range from transparent to translucent. They both refract and reflect light, which gives them the sparkling look that we all associate with crystals.
  
• Both the crystals are chemically inactive. This allows them to be used in a wide range of applications: quartz is used in watches & lab apparatus; diamond can help in cutting metals and making abrasives.
  
• Both quartz and diamonds are reasonably hard minerals (above 7+ on the Mohs Hardness Scale). This means that they are great for making jewelry and are also safe underwater.

Differences Between Quartz and Diamond

Chemical Composition & Structure

Quartz and diamond have different chemical compositions, which is why their properties are also quite different.

Quartz is a hard, crystalline mineral that is made up of silica, that is, silicon dioxide (SiO₂). Each silicon atom is surrounded by four oxygen atoms in a tetrahedral arrangement.

In contrast, diamond is made up entirely of carbon. Each carbon atom is bonded to four other carbon atoms in a three-dimensional tetrahedral arrangement.

The two minerals also have different crystal structures. Quartz silicon dioxide molecules form six-sided hexagonal crystals, whose lengths are usually greater than their widths. The crystals grow in such a way that only one end terminates in a hexagonal pyramid. 

Diamond, on the other hand, has its carbon atoms arranged in squat isometric crystals. The eight-sided crystals often appear as two pyramids adjoined base to base. Unlike quartz, diamond crystals (whether single or twinned) measure the same in all directions. 

Color

Quartz comes in many colors while the best-quality diamond is transparent.

You can find quartz crystals in a wide range of colors: white, citrine yellow, amethyst purple, etc. Rose quartz is the most well-known variant, and its beautiful pink hue is very hard to replicate. 

Diamonds can also sometimes appear in different colors. But this is due to impurities and structural defects—pure diamond is transparent. 

Color may often be used to differentiate diamond from quartz, but clear quartz is also transparent; it’s best to use other methods to identify the minerals. 

Hardness

Both quartz and diamond are hard minerals that are good for jewelry, but diamond is harder.

The hardness of minerals is calculated using the Mohs Hardness Scale, which measures a mineral’s relative resistance against scratching. A value over 5.0 also indicates that the mineral is safe underwater. 

Quartz has a value of 7.0 on the Mohs Scale, which means that is quite durable (which makes it ideal for jewelry & decoration) and is also safe to be immersed. However, diamond has a value of 10.0 on the scale—it is the hardest mineral on the planet. 

Pattern and Clarity

Quartz and diamond are both beautiful gemstones, but they differ in terms of their luster and refractive index.

The way light interacts with a crystal depends on the molecular structure of the mineral. Luster and refractive index are two ways of measuring how this occurs. The former describes how the crystal looks, that is, how light reflects off its surface.

Quartz has a vitreous or glassy luster. On the other hand, diamonds have an adamantine luster. However, luster is still a rather subjective term. Therefore, people often prefer to use the refractive index, which measures the change as light passes from one transparent medium to another.

This is an objective measure and hence more accurate. Quartz has a refractive index of 1.544-1.553. Diamond, in contrast, has a value of 2.418. A DIY way of testing this would be to put both crystals in vegetable oil (they have generally a refractive index of 1.47).

Quartz will almost disappear in the oil (as its refractive index is rather close to it). A diamond crystal, however, will remain quite distinct and easily observable.

Zodiac Sign

Quartz and Diamond are associated with different zodiac signs, and they have varying metaphysical properties.

Clear quartz is usually linked to Taurus and is considered its birthstone. For a Taurus, a quartz stone will provide comforting and familiar energy. It can also help let go of the stubbornness that often comes with Taurus. 

Instead, it can make one more flexible & considerate, thereby helping with relationships. Other kinds of quartz are associated with different beliefs. For example, Capricorn is linked with Smoky Quartz.

Diamond, on the other hand, is linked to Virgo and Libra. It is believed that it brings good luck and prosperity for them. Other zodiac signs can also wear diamonds under certain conditions. However, Aries, Pisces, and Scorpio are often advised against wearing diamonds.

Location

Quartz and diamonds are made through different processes and are therefore found in different locations. 

Quartz is the second most abundant mineral on Earth (after feldspar) and is widely distributed in the Earth’s crust. It is a major component of many rock types, such as granite, sandstone, quartzite, etc.

It can also be formed in hydrothermal veins: hot water containing dissolved silica precipitates into quartz crystals. Finally, quartz is also a common mineral in sedimentary rocks, which can be found in various environments—from desert dunes to mountains. 

Diamonds, on the other hand, are much rarer. They are formed deep inside the Earht’s mantle, where they require specific high-pressure and high-temperature conditions. These crystals are then brought to the Earth’s surface by rare volcanic eruptions (known as kimberlite eruptions).

Various parts of the world, such as South Africa, Canada, and Russia have these kimberlite pipes. These carrot-shaped volcanic pipes bring the diamonds to the surface. The crystals then get transported by rivers to alluvial deposits. 

Finally, diamonds can also be found on shores, such as the coast of Namibia. The oceanic current is responsible for transporting them from land-based sources. 

Pricing & Size

The biggest difference between the two minerals lies in their pricing: quartz is quite affordable while diamond is one of the most expensive minerals.

As we saw earlier, quartz is an abundant mineral, so it is also quite affordable. A 1-carat rose quartz would cost around $100. While this isn’t too cheap, it is incredibly smaller compared to the price of 1-carat diamonds: the difference goes up to thousands of dollars.

As with all crystals, the price of diamonds depends on aspects like size, clearness, color, and cut. Size is the biggest determinant of the price of diamonds. After that comes the cut of the crystal, which itself can lead to a difference worth thousands of dollars.

In the case of quartz, however, the cut isn’t that important. Sometimes, one may even prefer to leave a quartz crystal as it is, retaining its characteristic shape and look. However, size still plays a major role in its price.

While quartz crystals are comparatively cheaper than diamonds, bigger pieces can still be really expensive. It’s also important to note that for both quartz and diamonds, the rare varieties (say yellow diamonds) can increase the price even more. 

Care

Here’s how you can clean and take care of your diamonds:

• Soak your diamond jewelry in a soft degreasing solution (say water with a few drops of mild dish soap). This should ideally be done once or twice a week.
  
• You can also use a soft, clean toothbrush to gently clean the dirt. Some places, such as the back of the diamond, are hard to reach, so use the brush carefully here. Dry the stone with a soft, lint-free cloth.
  
• Do not use harmful solutions such as chlorine beach on your diamonds. Abrasives, such as household cleaners or toothpaste, should also never be used. These can damage the metals used in the diamond settings and can also scratch their surfaces.
  
• Sometimes using ultrasonic cleaners becomes necessary to remove dirt, but do this with caution. Otherwise, the stones may come off from their mountings. Avoid ultrasonic cleaners altogether if the diamond has been treated by fracture filling.

Quartz also has a value of 7.0 on the Mohs Hardness Scale, so it is also safe to go underwater. You can follow the same steps for cleaning it: soak it in a solution, clean it with a toothbrush, and then let it dry.

Uses of Quartz and Diamond

These are the uses of quartz:

• Jewelry: Various types of quartz, such as amethyst, citrine, and rose quartz are used as gemstones.
  
• Glass Production: High-quality quartz is used in the manufacture of glass and optical lenses, thanks to its clarity & resistance to heat/corrosion.
  
• Watches: Quartz is used in quartz watches for precise timekeeping.

These are the uses of diamonds:

• Jewelry: Diamonds are perhaps the most highly prized gemstones in the world, especially used in engagement rings.
  
• Industrial cutting: As diamond is the hardest mineral on earth, it is used as a cutting and polishing tool in various industries, such as construction, mining, etc.

• Abrasives: Synthetic diamonds are also used as abrasive materials in industrial equipment, such as grinding wheels, cutting tools, etc.

You can also check out this video by Amazone Diamonds to see how to differentiate quartz and diamonds. 

How to Tell if a Crystal is a Diamond or Quartz?

To differentiate between quartz and diamond, you can take into account these points:

• Price: The most obvious difference between the two is the massive price difference.
  
• Refractive Index: As we saw earlier, quartz and diamonds have different refractive indices. You can simply put the two crystals in vegetable oil and observe: the invisible stone would be quartz, while the diamond would stand out.
  
• Specific Gravity: Diamonds have a higher density and specific gravity than quartz. The former’s value is 3.1-3.53 while the latter’s is 2.6-2.7. If the crystals are of the same size, the diamond will be heavier than the quartz. You can use this method if you have a precise weighing scale.
  
• Destructive Testing: Finally, we can differentiate the two through their hardness and cleavage; however, this involves damaging the crystals. Diamonds have a hardness of 10.0 while quartz has a value of 7.0; so, the former will scratch the latter. We can also examine the pattern of break: diamond’s cleavage planes are parallel to the crystal faces while quartz has no cleavage planes.

Read: Carnelian vs Red Jasper (Full Comparison)

Conclusion

Quartz is an abundant and affordable mineral while diamond is rare and expensive. While the two minerals have some similarities, they mostly differ in various aspects like chemical composition, hardness, clarity, etc.