Difference Between Cubic Zirconia and Diamond (With Table)

Gemstones or precious stones play a pivotal role in the jewelry and adornment industry. The features that they provide are mainly luster, durability, and also a rarity. Some stones exhibit luxury because of their value. The two main crystals popularly used in the jewelry industry are cubic zirconia and diamond.

Cubic Zirconia vs Diamond

The main difference between cubic zirconia and diamond is that cubic zirconia is a synthetic gemstone that is used as an alternative to diamond while diamond is the hardest natural stone known to date. On the Mohs Scale of hardness, cubic zirconia is rated 8.5 while diamond is rated as 10.

Cubic zirconia is crystallized from the mineral called zirconium dioxide. It is denser and heavier stone than a diamond. The lab-grown crystal was found in 1892. Though it has a great deal of shine and luster, it can be easily distinguished under natural light as it gives a rainbow of white light.

While a diamond is a form of carbon that is arranged in a crystalline form. It is a hexoctahedral crystal that allows thermal conduction and gives a white brilliance under natural light. The refractive index of diamond is higher than cubic zirconia. Diamonds are more durable and expensive than cubic zirconia.

Comparison Table Between Cubic Zirconia and Diamond

Parameters of ComparisonCubic ZirconiaDiamond
DiscoveredIn 1937 by M.V. Stackelberg and K. Chudoba Discovered in the caves of India around 4 and 6 BC
NatureCrystallographically isometric and is obtained in the form of polycrystalline ceramic Hard crystal, allows heat conduction, high refractive index, and has a specific gravity
Dispersion rateCubic zirconia has a high rate of dispersion which is about 0.058-0.066 Diamond has a low rate of dispersion which is about 0.044
ProducersMajor producers are CERES Corporation, Taiwan Crystal Company, ICT Incorporated, and Swarovski Largest diamond mining company is De Beers and its subsidiary company Diamond Trading Company (DTC)
ApplicationsUsed in jewelry, windows, building material, prisms, lenses, filters, in the manufacture of laser elements, as a substrate for semiconductors and superconductors, and widely in the bio-engineering industry Used as gemstones, jewelry, diamond windows, heat sinks, industrial abrasives, speaker domes, low-friction micro bearings, in wire manufacturing and also in various parts of wear-resistant gears

What is Cubic Zirconia?

Cubic zirconia is a crystal of zirconium dioxide. It is also known as cubic zirconium. It is a colorless synthetic gemstone. It can be produced at a low cost but resembles a diamond. The nature of cubic zirconia resembles the mineral baddeleyite. It is used as an alternative to diamond. It is a lab-grown crystal.

Though cubic zirconia was found around 1892, it was officially found in 1937 by M.V. Stackelberg and K. Chudoba. The first research regarding the same was conducted in 1960 in France by Y. Roulin and R. Collongues. The process of obtaining cubic zirconia is by melting zirconium oxide powder at 4982°F with the help of stabilizers (like calcium and magnesium).

Cubic zirconia is coated with a film of diamond-like carbon (DLC) to make it harder and lustrous. Another method called vacuum sputtering is also done which involves a layer of precious metal over the stone to create an iridescent effect. Some properties of cubic zirconia are that it has a low refractive index, behaves as a thermal insulator, and has high dispersion.

Not only in the jewelry industry, but cubic zirconia is also used for windows, building material, prisms, lenses, filters, in the manufacture of laser elements, as a substrate for semiconductors and superconductors, and widely in the bio-engineering industry.

What is Diamond?

Diamond is a form of carbon arranged in a crystalline structure. It has a hexoctahedral crystalline structure. Diamond is excavated from xenoliths formed at the depth of the earth’s crust and can form as deep as 800 km from the surface. It can be found in abundance at subduction zones or asteroid impacted sites. The gem is renowned for its brilliance, hardness, and sparkle. It is the hardest natural substance.

Diamond is found in three main types of deposits – glacial tills, alluvial gravels, and kimberlite pipes. It is usually colorless, transparent, or contains a tinge of yellow but contamination from impurities impart colors like blue, brown, green, orange, pink, and purple to it.

The word Diamond is derived from a Greek word called adámas which means unbreakable and unalterable. Diamond was first mined in the Indian subcontinents. Natural diamonds are formed at high temperatures and pressure by carbon-containing fluids and can have an age between 1 billion to 3.6 billion years old.

The world’s greatest hub for cutting and polishing diamonds is in Surat (India). Diamonds are widely used for their beauty and quality as gemstones, jewelry, diamond windows, heat sinks, industrial abrasives, speaker domes, low-friction micro bearings, wire manufacturing, and also in various parts of wear-resistant gears.

Main Differences Between Cubic Zirconia and Diamond

  1. Cubic zirconia does not have sharp edges and shows the marks of polish while diamond has sharp edges and does not show the polish marks.
  2. Cubic zirconia gives a rainbow of colored light under natural light while diamond gives a brilliance of white light under natural light.
  3. The refractive index of cubic zirconia is around 2.15 to 2.18 while the refractive index of diamond is 2.42.
  4. Cubic zirconia can be available in various color options like pink, green, yellow, purple, and even multicolor while diamond is colorless and may have a tinge of yellow.
  5. Cubic zirconia acts as a thermal insulator while diamond acts as a thermal conductor.

Conclusion

Both the crystals may appear the same because of a similar exhibition of shine and luster. Cubic zirconia is a man-made crystal and serves customers looking for affordable crystals while diamond is the hardest natural crystal and exhibits luxury and royalty.

Cubic zirconia and diamond can be of the same size and cut but can be easily distinguished under natural light. Both have their characteristics, and it is upon the customers to make the choice depending upon their needs and budget.

References

  1. https://www.osti.gov/biblio/6004051
  2. https://pubs.acs.org/doi/pdf/10.1021/j100366a014
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