Gemological Data

Aquamarine

Generic Information:

Name Origin: Its name is due to its color similar to seawater.

Main Colors: Blue, greenish-blue, and grayish-blue.

Producing Countries: The Aquamarine mines in Brazil have been known for nearly three centuries and still produce a good part of the world’s production to this day, especially in the cities of Coronel Murta, Araçuaí, and Marambaia in Minas Gerais and in the region of Tenente Ananias in Rio Grande do Norte. Also, the Espírito Santo mines are important. Historically, Brazil was the world’s largest producer of Aquamarine, but the recent tightening of labor laws and environmental legislation has made mining more expensive.
Beautiful stones are obtained high in the mountains of Pakistan. It provides the world with some of the finest stones, found at 3,000 or even 4,000 meters in altitude, which makes mining very difficult. Other important sources include Kenya, Zambia, Nigeria, Madagascar, and Mozambique in Africa, and China in Asia.
Most Aquamarines nowadays come from Mozambique and Nigeria. More recent regular productions ocurred at the Cabo Delgado mine in the Cabo Delgado Province in Mozambique.
Geologically, Aquamarines are found in pegmatites, intrusive igneous rocks basically formed by quartz and feldspar as a matrix. Almost all mining is underground, following the pegmatites. The crystals can weigh from grams to tens of kilos, but only a small fraction of the production is pure enough to be cut.

Common Shapes: Oval and drop, round, antique and octagonal. They can also be calibrated up to the larger 20×15 sizes. As they have no cleavage, cutting is relatively simple. Most have no inclusions seen by the naked eye.

Usual Treatment: heating around 400 to 450°C, making the blue color stand out, removing the greenish overshade. Most of the world’s production is routinely treated in this way.