Santa Maria Aquamarine is one of the oldest and most expensive color of aquamarine. Their tradename comes from Brazil. They have one of the deepest blue tone which is natural and not treated. The more deeper the color is more expensive.
Santa Maria Color is easily found in Larger gemstones but it is extremely rare to find in small sizes due to the nature of beryl gemstone which gets lighter when cut smaller. The primary good source of fine quality deep blue aquamarine currently is Madagascar but they tend to have inclusions.