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Lot 10
Rare Large Benitoite--An Exceptional California Gemstone
2 May 2023, 12:00 PDT
Los AngelesSold for US$52,035 inc. premium
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Rare Large Benitoite--An Exceptional California Gemstone
San Benito County, California
Around the turn of the century, a prospector discovered a blue material that he believed to be sapphire. Examination by experts determined the new gem material to be an unknown mineral. In addition, it turned out that the new material represented a previously unknown example of crystal form. It was given the name of benitoite, since it was found near the headwaters of the San Benito River in the county of the same name. Benitoite is prized for its adamantine or diamond-like luster and high dispersion. Its refractive index and dispersion are high enough to resemble colorless-to blue diamonds. The fact that their specific gravity and hardness differs from that of diamonds and that all benitoites fluoresce blue, allows differentiation. Benitoite was declared the official state gemstone of California in 1985. Although its public recognition and consequent desirability have increased dramatically over the past few years. Its only source is a small mine in San Benito County in northern California. Most of the rough yields cut gems below one carat and gems of this size are virtually unheard of. The present stone has the classic color for benitoite: a beautiful blue with a hint of lavender. The size of this stone, at well over 4 carats, as well as its transparency are exceptional. This is truly a great opportunity for the collector of American minerals or gemstones. Weighing approximately 4.21 carats and measuring 11.79 x 8.31 x 5.16mm
Around the turn of the century, a prospector discovered a blue material that he believed to be sapphire. Examination by experts determined the new gem material to be an unknown mineral. In addition, it turned out that the new material represented a previously unknown example of crystal form. It was given the name of benitoite, since it was found near the headwaters of the San Benito River in the county of the same name. Benitoite is prized for its adamantine or diamond-like luster and high dispersion. Its refractive index and dispersion are high enough to resemble colorless-to blue diamonds. The fact that their specific gravity and hardness differs from that of diamonds and that all benitoites fluoresce blue, allows differentiation. Benitoite was declared the official state gemstone of California in 1985. Although its public recognition and consequent desirability have increased dramatically over the past few years. Its only source is a small mine in San Benito County in northern California. Most of the rough yields cut gems below one carat and gems of this size are virtually unheard of. The present stone has the classic color for benitoite: a beautiful blue with a hint of lavender. The size of this stone, at well over 4 carats, as well as its transparency are exceptional. This is truly a great opportunity for the collector of American minerals or gemstones. Weighing approximately 4.21 carats and measuring 11.79 x 8.31 x 5.16mm
Footnotes
https://www.bonhams.com/auctions/19429/lot/1386/