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Benitoite

Sapphire-blue barium titanium silicate from one hillside in California.

Family
Benitoite
Formula
BaTiSi₃O₉
Mohs
6 to 6.5
System
Hexagonal

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Science

Benitoite is a rare cyclosilicate that crystallises in the unusual ditrigonal-dipyramidal class, forming flat blue triangles on white natrolite with black neptunite. It has dispersion higher than diamond, and it fluoresces vivid blue under shortwave ultraviolet light.

Mineral
Benitoite
Formula
BaTiSi₃O₉
Crystal system
Hexagonal
Mohs hardness
6 to 6.5
Specific gravity
3.65
Refractive index
1.757 to 1.804
Lustre
Vitreous
Colours
Blue, Colourless

Composition

BaTiSi₃O₉. Made of Barium, Titanium, Silicon, Oxygen.

in formula

Origin

  • United States
    San Benito County, California

Filled dots are primary sources

Rarity

Exceptional
5 of 5

Gem-quality benitoite occurs at one locality on Earth, mined out commercially in 2005. Cut stones over two carats are exceptional.

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

Hardness

Benitoite sits at 6 to 6.5 on the Mohs scale. Glass and a knife blade are about as hard; it wears well with care.

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

  • Throat
  • Third Eye

Element

  • Air

Zodiac

  • Aquarius

Planets

  • Uranus

Properties

  • Insight
  • Telepathy
  • Joy
  • Clarity of purpose

Lore

Prospector James Couch found it in 1907 looking for copper and thought it was sapphire; the University of California identified a new mineral. California made it the state gem in 1985.

It has no traditional lore; its practice associations are borrowed from blue sapphire.

  • Fluorescence
    Bright blue under shortwave UV, the diagnostic test.
  • Dispersion
    0.044, higher than diamond's 0.044 in some directions.