The name "Aquamarine" (Aquamarin German, Aqua marina Spanish) is derived from the Latin phrase "water of the sea", named for it's greenish-blue seawater color. Aquamarine (or Aqua Beryl) develops in granite pegmatites and certain types of metamorphic rock. It occurs in conjunction with quartz, microcline, muscovite, and almandine in metamorphic pegmatite. Most Aquamarine comes from the pegmatites of Minas Gerais Brazil, where crystals weighing several pounds have been found. Beryl has become an important source of the element beryllium, a metal with a variety of commercial uses, such as in the manufacturing metal alloys. Blue Spinel, a synthetic mineral, is easy and inexpensive to produce, and it is often mistakenly sold as "Synthetic Aquamarine".
Beryl Aquamarine is a Cyclosilicate made up of beryllium (Be) aluminium silicate, sodium (Na), lithium (Li), and cesium (Cs). Aquamarine has a hardness of 7.5 to 8 on the Mohs scale. The Toughness of Aquamarine is Good. Aquamarine crystallizes in the Hexagonal crystal system with a Prismatic, Parallel and Elongated Crystal Habit. Aquamarine has a refractive index of 1.577.
Aquamarine crystal is generally vertically striated or grooved and pleochroism is distinct in deeply colored crystals. Aquamarine has a Vitreous luster. Ocasionally, some specimens of aquamarine display chatoyancy. Aquamarine has imperfect cleavage which runs parallel to the basal pinacoid. Aquamarine has a refractive index of 1.563 to 1.583 and is transparent to translucent. Aquamarine's blue color is due to the presence of Ferrous iron atoms and the presence of ferric iron causes a yellow tint.
Chemical composition: Be3Al3[SiO3]6
Santa Maria Aquamarine
Perhaps the largest Aquamarine ever found was the 552,500 carat Papamel Aquamarine, found in 1910 at the Batadal mine near the village of Ponto de Marambaia, in Minas Gerais, Brazil. One of the larger near-flawless Aquamarine crystals ever found was the "Dom Pedro" Aquamarine found in 1993 in Minas Gerais, weighing 10,395 carats (24,875 grams).
Brazil's principal aquamarine region begins about 75 miles north of Rio de Janeiro and includes the areas of Araçuaí, Conselheiro Pena, Governador Valadares, Jequitinhonha River basin, Pedra Azul, Salinas, and Teofilo Otoni. The town of Teofilo Otoni in Minas Gerais is a major Brazilian gem-trading center known for its aquamarine. Some of the highest quality specimens of brilliant blue "Santa Maria" aquamarine come from the Santa Maria de Itabira Mine. Aquamarine from africa that has the same intense blue color is called "Santa Maria Afrique."
Principal aquamarine mines in the Brazilian state of Minas Gerais are the Batadal Mine, Papamel Mine, Santa Maria de Itabira. Brazilian aquamarine with a paler blue color are referred to as "Espírito Santo" for the state of the same name.
Aquamarine Inclusions
Due to aquamarine's pale color and high tranparency, it is relatively easy to see any inclusions that are present in the stone.
