Lapidarium
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Sapphire

Corundum in every colour except red, best known in blue.

Family
Corundum
Formula
Al₂O₃
Mohs
9
System
Trigonal

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Science

Blue sapphire owes its colour to iron and titanium exchanging an electron across the crystal lattice. Trace chromium makes pink; iron alone makes yellow and green; the pink-orange padparadscha of Sri Lanka is the rarest hue. Nearly all sapphire is heated.

Mineral
Corundum (variety)
Formula
Al₂O₃
Crystal system
Trigonal
Mohs hardness
9
Specific gravity
4.00
Refractive index
1.762 to 1.770
Lustre
Vitreous to adamantine
Colours
Blue, Pink, Yellow, Padparadscha
Birthstone
September

Composition

Al₂O₃. Made of Aluminium, Oxygen, with trace Iron, Titanium responsible for colour.

in formula trace, gives colour

Origin

  • Sri Lanka
    Ratnapura
  • Myanmar
    Mogok
  • India
    Kashmir, historic, finest
  • Madagascar
  • Thailand
  • Australia
  • United States
    Yogo Gulch, Montana

Filled dots are primary sources

Rarity

Rare
4 of 5

Commercial sapphire is plentiful; unheated Kashmir and Burmese stones of fine colour are among the rarest gems traded.

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

Hardness

Sapphire sits at 9 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

  • Third Eye
  • Throat

Element

  • Air

Zodiac

  • Virgo
  • Libra
  • Taurus
  • Gemini

Planets

  • Saturn
  • Jupiter

Properties

  • Wisdom
  • Truth
  • Focus
  • Loyalty
  • Serenity

Lore

Kashmir sapphires were exposed by a landslide in 1881 and mined for only a few years; their velvety blue defines the top of the market. Persian kings believed the sky was blue from the reflection of a giant sapphire.

Medieval clergy wore blue sapphire as the stone of heaven; Prince Charles gave Diana a Ceylon sapphire ring in 1981 that Kate Middleton now wears.

  • Star of India
    563 carats, a grey-blue star sapphire in New York, stolen and recovered in 1964.
  • Colour change
    Some sapphires shift blue to purple under incandescent light.