What is Benitoite?
Benitoite is a rare blue barium titanium cyclosilicate found in serpentinite that has been hydrothermally altered. It occurs at subduction zones near convergent plate borders, when the temperature is low and the pressure is high.
Benitoite was discovered in 1907 and was declared the state jewel of California in 1985. At first, theories concerning the material’s origins varied from volcanic glass to spinel to sapphire, according to its hue. The stone’s higher dispersion and birefringence characteristics, however, set it apart from sapphire. A closer look revealed it to be a brand-new gemstone.
Benitoite comes in a variety of hues, ranging from blue to white to pinkish to colorless. Color zoning may be seen in rough.
General Information
| Category | Cyclosilicate |
| Formula | BaTiSi3O9 |
| Crystal system | Hexagonal |
| Crystal class | Ditrigonal dipyramidal (6m2) |
Physical Properties of Benitoite
- Cleavage: {1011} Poor
- Color: Blue, Purple, Pink, White, Colorless.
- Density: 3.6
- Diaphaneity: Transparent to translucent
- Fracture: Conchoidal
- Hardness: 6-6.5 – Orthoclase-Pyrite
- Luminescence: Fluorescent, Short UV=blue.
- Luster: Vitreous (Glassy)
- Streak: white
Who Discovered Benitoite?
The writer had the same difficulties as Doctor Louderback in determining who was the initial discoverer of the benitoite property. J. M. Couch of Coalinga, who was grubstaked by R. W. Dallas, was clearly essential in locating the deposit. It’s debatable whether he discovered it on his own or on a second journey with L. B. Hawkins of Los Angeles. Mr. Hawkins’ material, which he brought to Los Angeles, was determined to be volcanic glass and so worthless. G. Eacret of Shreve & Co., San Francisco, and G. D. Louderback were shown specimens supplied to Harry U. Maxfield of Fresno, according to Mr. Couch.
Mr. Eacret’s sapphire specimens were assumed to be sapphire. Doctor Louderback identified the substance as a new mineral, which he called benitoite after the county where it was discovered.
Where are Benitoites Found?
Gem-quality material is only found in mines in San Benito County, California. Unfortunately, this source stopped producing in 2005.
Other resources include:
- United States: Hot Springs County, Arkansas; Fresno County, Kern County, California.
- Australia; Czech Republic; Japan.
Benitoite Meaning
It’s a very uncommon mineral found only in a few places, including California’s San Benito County, Japan, and Arkansas. This mineral may be found in various natrolite veins in glaucophane schist inside serpentinite bodies in San Benito. It’s found in serpentinite dikes cut by magnesio-riebeckite-quartz-phlogopite- albite dikes in Japan. Benitoite of gemstone grade can only be discovered in California.
Durability & Care
Benitoite is a great stone to use in daily jewelry. To avoid scuffs and scratches, Benitoite should always be stored with care. Clean with lukewarm water and mild soap, cleaning behind the gem with a soft toothbrush as needed. Dry with a gentle towel or chamois cloth after cleaning.
Benitoite Uses
Benitoite is used for a variety of purposes, however due to its rarity, these applications are limited.
- This lovely mineral is used to make jewelry as a gemstone.
- Benitoite is also commonly used as a mineral specimen. This mineral’s one-of-a-kind crystals are extremely desirable as collectible specimens.
- It’s also used as a barium and titanium ore in small quantities.
