Santa Maria Aquamarine

The name originated with aquamarine from the Santa Maria de Itabira mine in Minas Gerais, Brazil; aquamarine in general forms in granitic rocks, especially granite pegmatites. That mine is now nearly exhausted. Since the 1970s most stones sold as Santa Maria have been either older Brazilian gems returning to the trade or gems from more recent deposits in Africa, such as Mozambique, Madagascar and Nigeria.

"Santa Maria" describes colour, not a separate material: gemological testing identifies the stone as aquamarine, and a seller's use of the name does not prove Brazilian origin. In 2022 the Asian Institute of Gemological Sciences (AIGS) introduced a colour code that applies the name to blue aquamarine of medium saturation without brown or yellow tints, regardless of origin; stones with low saturation, low clarity or dark tones do not qualify. Pure blue aquamarine is commonly heat treated to remove a green tint, a treatment considered undetectable, and other beryls may be irradiated to imitate aquamarine colour.

Inclusions in aquamarine may not tolerate ultrasonic or steam cleaning, which can increase the risk of shattering, so have a gemologist check a stone before using these methods. A soft brush, mild detergent and warm water are always safe.

The trade has long valued the saturated blue aquamarine of the Santa Maria de Itabira mine as among the finest aquamarine colours, and the mine's name became a colour term. As production declined, the name was increasingly applied to stones from other sources and to material that falls short of the original quality, which led AIGS to publish a colour standard for the label in 2022.