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Benitoite
Current inventory:  6 gems
 

Benitoite

  
Benitoite is named after San Benito County, California, USA where it was discovered.

Discovered in 1907;   IMA status:  Valid (pre-IMA; Grandfathered)

 

Chemistry

 

 

Chemical Formula:

BaTiSi3O9

 

Barium Titanium Silicate

Molecular Weight:

413.46 gm

Composition:

Barium

33.21 %

Ba

37.08 %

BaO

 

Titanium

11.58 %

Ti

19.32 %

TiO2

 

Silicon

20.38 %

Si

43.60 %

SiO2

 

Oxygen

34.83 %

O

 

 

 

 

100.00 %

 

100.00 %

= TOTAL OXIDE

 

 

Classification

   

   

Mineral Classification:

Silicates (Germanates)

Strunz 8th Ed. ID:

8/E.01-10

Nickel-Strunz 10th Ed. ID:

9.CA.05

 

9 : SILICATES (Germanates)
C : Cyclosilicates
A : [Si3O9]6- 3-membered single rings (dreier-Einfachringe), without insular complex anions

Related to:

Benitoite Group. The titanium analogue of Pabstite. Related to Rogermitchellite.

Members of Group:

Benitoite Group: Benitoite, Bazirite, Pabstite, Wadeite

Varieties:

None

Synonyms:

Benitoide

 

 

Crystal Data

   

   

Crystallography:

Hexagonal - Ditrigonal Dipyramidal

Crystal Habit:

Flat pyramidal crystals, tabular, triangular or hexagonal in outline, to 6 cm.

Twinning:

By rotation about [0001]

 

 

Physical Properties

   

 

Cleavage:

Poor on [1011]

Fracture:

Conchoidal

Tenacity:

Brittle

Moh's Hardness:

6.0 - 6.5

Density:

3.64 - 3.68 (g/cm3)

Luminescence:

Fluorescent. Blue under SW UV; intense blue Cathodoluminescence

Radioactivity:

Not Radioactive

 

 

Optical Properties

   

   

Color:

Sapphire-blue, Purplish-blue, white to colorless, pink; commonly bicolored.

Transparency:

Transparent to Translucent

Luster:

Vitreous

Refractive Index:

1.756 - 1.804  Uniaxial ( + )

Birefringence:

0.047

Dispersion:

0.046 (greater than diamond)

Pleochroism:

Visible; O = Colorless; E = Purple, Indigo, Greenish Blue

 

 

Occurances

   

   

Geological Setting:

In natrolite veins cutting glaucophane schist in a serpentine body (San Benito Co., California, USA); in a magnesio-riebeckite-quartz-phlogopite-albite dike cutting serpentinite (Ohmi, Japan).

Common Associations:

Joaquinite, Natrolite, Neptunite (San Benito Co., California, USA); Ohmilite, Bario-Orthojoaquinite, Leucosphenite (Ohmi, Japan).

Common Impurities:

Na

Type Locality:

Dallas Gem Mine (Gem Mine; Benitoite Mine), New Idria District, San Benito County, California, USA

Year Discovered:

1907

View mineral photos:

Benitoite Mineral Photos and Locations

 

 

More Information

   

   

 

Mindat.org
Webmineral.com

 

 


Discovered in 1907 in San Benito Country, California and named after that locality, Benitoite is one of the most beautiful of all the rare gems with the color of fine Sapphire and dispersion slightly higher than Diamond! San Benito County is the only location in the world for gem quality Benitoite. Benitoite is a rare collector's gem with a beautiful blue to purplish-blue color. The Benitoite Gem Mine is now closed and only surface collecting is currently allowed. Benitoite is considered to be one of the ten rarest gemstones in the world according to curiousnotions.com.
 

  
Benitoite gems for sale:

Benitoite-001

Gem:

Benitoite

Stock #:

BENI-001

Weight:

0.3700 ct

Size:

4.71 x 3.25 x 2.68 mm

Shape:

Cut corner rectangle

Color:

Blue w/ purple highlights

Clarity:

Flawless (loupe clean)

Origin:

San Benito Gem Mine, CA, USA

Treatment:

None (natural)

Price:

SOLD

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Benitoite-001

This beautiful, rare gem is from the now closed Benitoite Gem Mine in San Benito County, California, USA - the only location in the world for gem-quality Benitoite. The color is beautiful, the clarity is flawless and the faceting is excellent.


Benitoite-002

Gem:

Benitoite

Stock #:

BENI-002

Weight:

2.0100 ct

Size:

7.17 x 8.55 x 5.26 mm

Shape:

Fancy - Kite

Color:

Purplish-Blue

Clarity:

Flawless! Loupe Clean

Origin:

San Benito Gem Mine, CA, USA

Treatment:

None (natural)

Price:

$8,000.00    [ Make an offer ]

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Benitoite-002

This extemely rare gem is from the now closed Benitoite Gem Mine in San Benito County, California, USA - the only location in the world for gem-quality Benitoite. A two carat Benitoite is very rare; a flawless two carat Benitoite is extremely rare! The color of this gem is ideal for Benitoite (a beautiful purplish-blue), the faceting is supurb! It was precision faceted in the US. This gem has lots of fire and brilliance - it is nothing short of breath-taking!


Benitoite-003

Gem:

Benitoite

Stock #:

BENI-003

Weight:

3.0910 ct

Size:

10.42 x 7.50 x 5.40 mm

Shape:

Fancy - Shield

Color:

Purplish-Blue

Clarity:

85% Loupe Clean - 15% SI2

Origin:

San Benito Gem Mine, CA, USA

Treatment:

None (natural)

Price:

$7,000.00    [ Make an offer ]

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Benitoite-003

This extemely rare gem is from the now closed Benitoite Gem Mine in San Benito County, California, USA - the only location in the world for gem-quality Benitoite. OK, so if a two carat Benitoite is extremely rare; then a three carat Benitoite is exceedingly rare! The color of this gem is ideal for Benitoite (a beautiful purplish-blue). This gem is about 85% loupe clean with two feather inclusions and one very small nick at the girdle. Just the fact that this Benitoite is ideal color and over three carats makes this gem a true rarity! It was precision faceted in the US. This Benitoite includes an EGL USA appraisal of $9,800.00! (Report # US 40237301C)


Benitoite-004

Gem:

Benitoite

Stock #:

BENI-004

Weight:

0.3850 ct

Size:

4.68 x 2.73 mm

Shape:

Round Brilliant

Color:

Blue

Clarity:

Loupe Clean

Origin:

San Benito Gem Mine, CA, USA

Treatment:

None (natural)

Price:

$420.00    [ Make an offer ]

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Benitoite-004

This beautiful gem really shows the extreme brilliance and fire of Benitoite. The precision faceting brings out the best in this gem. The color is a medium blue with flashes of purple. As usual, the pictures can't capture the true beauty of the gem. This gem was precision faceted in the US.


Benitoite-005

Gem:

Benitoite

Stock #:

BENI-005

Weight:

2.2175 ct

Size:

10.28 x 8.07 x 4.64 mm

Shape:

Fancy - Pear

Color:

Pale Blue

Clarity:

Eye Clean - VVS

Origin:

San Benito Gem Mine, CA, USA

Treatment:

None (natural)

Price:

$4,435.00    [ Make an offer ]

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Benitoite-005

A very large and unique Benitoite with pale blue color and a slightly sleepy appearance due to very fine Natrolite fibers. This gem was cut in the US and is very well faceted in an elongated trillion/pear shape. The color is lighter than most Benitoites which allows its brilliance to show. It is a very bright and beautiful gem.


Benitoite-006

Gem:

Benitoite

Stock #:

BENI-006

Weight:

0.1375 ct

Size:

3.48 x 2.65 x 1.82 mm

Shape:

Oval

Color:

Colorless

Clarity:

Eye Clean

Origin:

San Benito Gem Mine, CA, USA

Treatment:

None (natural)

Price:

$85.00

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Benitoite-006

A very rare colorless Benitoite from the closed Benitoite Gem Mine in San Benito County, California, USA.


Benitoite-007

Gem:

Benitoite

Stock #:

BENI-007

Weight:

0.3305 ct

Size:

4.25 x 2.72 mm

Shape:

Round

Color:

Blue

Clarity:

Eye Clean

Origin:

San Benito Gem Mine, CA, USA

Treatment:

None (natural)

Price:

$350.00    [ Make an offer ]

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Benitoite-007

This beautiful gem really shows the extreme brilliance and fire of Benitoite. The precision faceting brings out the best in this gem. The color is a medium blue with flashes of purple. This gem was precision faceted in the US.


 


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