Aquamarine color chart: shades, names and which color is finest
By HeyGema™ · Updated
In short
Aquamarine is the blue to greenish blue variety of beryl, usually a light pastel greenish blue. GIA says the most valuable color is a dark blue to slightly greenish blue with moderately strong intensity. A round 1 carat aquamarine measures about 7.0 mm.
- 4shades on the chart
- 7.0 mm1 carat, round
- 7.5 to 8hardness (Mohs)
Aquamarine colors
Aquamarine is the blue to greenish blue variety of beryl, usually a light pastel greenish blue.
- Santa Maria-style blueA medium-dark, strongly saturated blue. Sellers may use the name for this color and not for the mine.
- Typical greenish blueWhat most stones look like.
- Pale blueA light tone.
- Sea-foam blue-greenA greener, unheated look. Some stones resist heat treatment and keep it.
The swatches are illustrations picked to match the color names. Screens and light change how color looks, and a cut stone changes with the light, so judge a stone in person or from a daylight photo.
Which aquamarine color is finest
GIA says the most valuable color is a dark blue to slightly greenish blue with moderately strong intensity. Price rises with color depth, and the range is narrow, so small differences matter.
How gemologists describe color
Gemologists describe the color of a stone with hue, tone and saturation, and look at the three together. For colored stones they also look at how evenly the color is spread.
- Hue
- The color you would name, such as blue, green or red, or a blend such as bluish green.
- Tone
- How light or dark that color looks, from pale to very dark.
- Saturation
- How strong or pure the color looks, from dull (grayish or brownish) to vivid.
- Evenness
- How evenly the color is spread through the stone. Color zoning is uneven color, such as bands or patches you can see.
Colored stones have no single color scale like the D to Z scale for diamonds, so sellers use their own words. Ask for a daylight photo and for the size in mm as well as the carat weight.
What affects aquamarine color
- Cause of color
- Iron is the main coloring element. Heating green beryl under controlled conditions turns it blue.
- Treatments
- Most aquamarine on the market is heated to a purer blue. The change is stable and permanent, and it is very hard to detect.
- Wear and care
- Aquamarine is hard enough for everyday rings and has the same durability as emerald without the fractures.
Aquamarine color and size
Large aquamarine is not rare, but strong color is easier to see in a larger stone. GIA says a fashioned stone generally needs to be over about 5 carats to show intense color. Carat is weight, not size. A round 1 carat aquamarine measures about 7.0 mm, against 6.5 mm for a diamond of the same weight. This table gives the face-up size of a well-cut aquamarine.
- 1 ct
- Round: 7.0 mm
- Oval: 8.7 x 6.0 mm
- Cushion: 6.1 x 6.1 mm
- 2 ct
- Round: 8.9 mm
- Oval: 11.0 x 7.6 mm
- Cushion: 7.7 x 7.7 mm
- 3 ct
- Round: 10.2 mm
- Oval: 12.6 x 8.7 mm
- Cushion: 8.8 x 8.8 mm
- 5 ct
- Round: 12.0 mm
- Oval: 14.9 x 10.3 mm
- Cushion: 10.5 x 10.5 mm
- 10 ct
- Round: 15.2 mm
- Oval: 18.8 x 12.9 mm
- Cushion: 13.2 x 13.2 mm
- 20 ct
- Round: 19.1 mm
- Oval: 23.7 x 16.3 mm
- Cushion: 16.6 x 16.6 mm
See the full aquamarine size chart for every shape, or use the carat to mm calculator for any weight.
Aquamarine properties
- Hardness (Mohs)
- Value: 7.5 to 8
- Refractive index
- Value: 1.567 to 1.590
- Specific gravity
- Value: 2.68 to 2.74
A beryl. Light, so it faces up bigger than a diamond of the same weight.
How to compare aquamarine stones
- Look at each stone in daylight and under indoor light. Color shifts with the light.
- Ask for the size in mm as well as the carat weight. A aquamarine of the same weight can differ in size by shape and cut.
- Ask whether the color is natural or treated, and ask for the answer in writing.
- For a stone that matters, ask for an independent lab report.
Designing with a colored stone? HeyGema lets you choose the stone shade and renders your design with it.