Zircon

Zircon is a colorful gem with high refraction and fire that’s unfairly confused with cubic zirconia.

ABOUT Zircon

Colorless Zircon is known for its brilliance and flashes of multicolored light, called fire. These zircon properties are close enough to the properties of diamond to account for centuries of confusion between the two gems.

Zircon occurs in an array of colors. Its varied palette of yellow, green, red, reddish brown, and blue hues makes it a favorite among collectors as well as informed consumers.

BIRTHSTONES & ANNIVERSARIES

Zircon is a birthstone for the month of December, along with turquoise and tanzanite.

4.4 BILLION

Zircon found in Australia is the oldest mineral on earth: 4.4 billion years old.

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METAMICTIZATION

Zircon sometimes contains traces of uranium, irradiating itself and changing its properties.

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MATARA

Colorless zircon is called “Matara” zircon after a city in Sri Lanka near where it is mined.

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FACTS

• Mineral: Zircon
  
• Chemistry: ZrSiO₄
  
• Color: Blue, red, yellow, orange, brown, green
  
• Refractive index: 
  
• High: 1.925 to 1.984 (+/- 0.040)
  
• Medium: 1.875 to 1.905 (+/- 0.030)
  
• Low: 1.810 to 1.815 (+/-0.030)
  
• Birefringence: 0.000 to 0.059 (low to high)
  
• Specific gravity: 3.90 to 4.73
  
• Mohs Hardness: 6 to 7.5 (low to high)

QUALITY FACTORS

Among consumers, blue is the most popular color of zircon.

COLOR zircon

The most valuable colors of zircon are blue, bright red, and green.

CLARITY

Zircon is often eye-clean. Gems with noticeable inclusions are less valuable.

CUT

To maximize its brilliance, zircon is most often cut in rounds and ovals.

CARAT WEIGHT

Zircon in fine quality is rare in large sizes. Zircon weighs more than most gems of like size.