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Zircon

The oldest mineral on Earth, and the brightest natural stone after diamond.

Family
Zircon
Formula
ZrSiO₄
Mohs
6 to 7.5
System
Tetragonal

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Science

Zircon is so durable it survives the erosion and remelting of the rocks it forms in, which is why crystals from Jack Hills, Australia are 4.4 billion years old. Its uranium content makes it the clock of geochronology and, over time, damages its own lattice into 'low' zircon. Blue zircon is brown Cambodian rough that has been heated.

Mineral
Zircon
Formula
ZrSiO₄
Crystal system
Tetragonal
Mohs hardness
6 to 7.5
Specific gravity
4.60 to 4.70
Refractive index
1.925 to 1.984
Lustre
Adamantine
Colours
Blue, Colourless, Brown, Red, Yellow
Birthstone
December

Composition

ZrSiO₄. Made of Zirconium, Silicon, Oxygen, with trace Hafnium, Uranium, Thorium responsible for colour.

in formula trace, gives colour

Origin

  • Cambodia
    Ratanakiri, blue
  • Sri Lanka
  • Myanmar
  • Tanzania
  • Australia
    Jack Hills, oldest crystals
  • Thailand

Filled dots are primary sources

Rarity

Common
2 of 5

Common as a mineral; gem zircon is moderately available. Its price suffers from confusion with cubic zirconia.

  1. 1 Abundant
  2. 2 Common
  3. 3 Uncommon
  4. 4 Rare
  5. 5 Exceptional

Hardness

Zircon sits at 6 to 7.5 on the Mohs scale. It will scratch glass and holds a polish in daily wear.

Fingernail
Copper coin
Knife, glass
Steel file
1
2
3
4
5
6
7
8
9
10

Energy

Associations from crystal-healing tradition, recorded here as folklore. They are not medical claims.

Chakras

  • Root
  • Crown

Element

  • Earth

Zodiac

  • Sagittarius
  • Virgo

Planets

  • Jupiter

Properties

  • Grounding
  • Wisdom
  • Prosperity
  • Honesty

Lore

Zircon appears as jacinth and hyacinth in Roman and medieval texts. In India it is one of the nine gems of the navaratna, standing for the descending lunar node.

Its reputation was damaged when cubic zirconia, an unrelated synthetic, borrowed the name in the 1970s.

  • Oldest
    4.404 billion years, Jack Hills, Western Australia.
  • Not CZ
    Cubic zirconia is ZrO₂, a lab-made imitation of diamond.