Benitoite is a single-source gemstone, meaning that so far, it has been found in only one place on Earth: in San Benito County, California. Benitoite grows in relatively small crystals, only a portion of which are gem quality--further increasing the rarity and value of this unique gemstone. Gem-quality benitoite over one carat is incredibly rare.
|Benitoite is safely cleaned with warm soapy water and a soft brush or cloth. Ultrasonic cleaners are risky for benitoite, and steam cleaners should never be used. Rapid temperature changes should be avoided.|
|Benitoite is usually colorless or found in shades of blue--ideally a rich sapphire blue with just a touch of violet--but in rare cases, it can also be purplish, greenish-gray, pink, or slightly yellowish. While it is not definite, benitoite's pretty blues are believed to be due to the presence of iron or titanium. Benitoite's blues are not the result of heat treatment or irradiation. In fact, when colorless benitoite is heated, it turns orange! |
|As with most colored stones, it is mainly the intensity and saturation of color that determines benitoite's value. Because most crystals of benitoite are quite small, larger stones (over one carat) are increasingly rare and more valuable. Benitoite is a type II gemstone, meaning inclusions are more the norm than the exception, so benitoite's clarity shouldn't be judged the same way a typically clean stone like amethyst would be.|
The name "benitoite" comes from San Benito County, California--the only place on earth where this rare gemstone is found.
Compared to other gemstones, benitoite has a relatively short history. It was discovered in 1906 and now, about 100 years later, the mine has been entirely depleted and sealed. The first crystals discovered were blue and it was thought to be sapphire, but gemological testing showed that this new stone had a crystal structure unlike any other and it was determined to be a brand new gem.
Colorless and light-blue benitoite has intense dispersion--so high that it rivals that of a diamond--which only serves to add to the demand for it. Dispersion is what most people might refer to as a gemstone's sparkle and what is commonly referred to in the gem industry as fire. Gemologically speaking, dispersion refers to the separation of white light into spectral colors. The gem literally bends rays of white light into all colors of the spectrum, similar to the way light passing through a prism creates a rainbow.
Like tanzanite, benitoite is strongly dichroic, meaning that it can appear different colors when viewed from different angles: either blue, violet-blue, or colorless.