Douglas Sterrett's 1911 USGS report on the mineral's discovery, geology, mining, and properties. Faceted Benitoite: Five tiny gems of faceted benitoite in a color gradient set from nearly colorless to violetish-blue. Each stone is a round brilliant of about 3.5 millimeters and weighing about .20 carat.
Article by Jessica Ball Picture of Stromboli A view of the island known as "Stromboli." A plume rises from the volcanic vent with the same name. The island has a population of a few hundred people. This view shows the northeast side of the island where most of their dwellings are located. Image copyright iStockphoto / miralex.
About 5% of the meteorites found on Earth are thought to be from an impact on Vesta Article by: Hobart M. King, Ph.D., RPG Vesta meteorites: The images above are photomicrographs of slices from three meteorites confirmed to have originated from the asteroid Vesta. Photographed in transmitted light under crossed polarizers, these images reveal the mineral composition and texture of the meteorites.
The man-made glass with a metallic sparkle and the source of the word "aventurescence." Author: Hobart M. King, Ph.D., GIA Graduate Gemologist Goldstone Cabochons: The bright reflective sparkle of goldstone is what makes it a popular man-made gem material. These blue and reddish brown goldstone cabochons are about 20 x 28 millimeters in size.
A beautiful blue and green gem material composed of azurite and malachite. Author: Hobart M. King, Ph.D., GIA Graduate Gemologist Azurmalachite cabochons: Cabochons of azurmalachite showing nice patterns of azurite (blue) and malachite (green). They were cut from material produced at the Morenci Mine in Arizona.
Gemstones for the Month of a Person's Birth Author: Hobart M. King, Ph.D., GIA Graduate Gemologist Photo Month Birthstones(s) January Garnet February Amethyst March Aquamarine, Bloodstone April Diamond May Emerald June Cultured Pearl, Alexandrite, Moonstone July Ruby August Peridot, Spinel September Sapphire October Opal, Tourmaline November Citrine, Topaz December Blue Zircon, Tanzanite, Turquoise Image credits: Aquamarine: Copyright iStockphoto / dolphinphoto; Diamond: Copyright iStockphoto / MXW Stock; Emerald, Opal, and Topaz: Copyright iStockphoto / mikheewnik; Pearls: Copyright iStockphoto / barbaraaaa; Sapphire: Creative Commons photo by Montanabw; Turquoise: Copyright iStockphoto / IrisGD.