California Gem AA Benitoite Investment Oval Gemstone. Benitoite is a rare gemstone, it only comes from a single limited deposit in California. It is a relatively new gemstone, and was first discovered in 1907.Benitoite gemstones have a sapphire-blue color. GEM TYPE BENITOITE # 14-717. CT WEIGHT 0.45 ct. SIZE 4.6 mm (25mm=1). The item "0.45 carat California Gem AA Benitoite Investment Round Collector Gemstone USA" is in sale since Tuesday, January 30, 2018. This item is in the category "Jewelry & Watches\Loose Diamonds & Gemstones\Loose Gemstones\Other Loose Gemstones". The seller is "jewelsroughgems" and is located in Casa Grande, Arizona. This item can be shipped to United States.