Spinel color chart: shades, names and which color is finest
By HeyGema™ · Updated
In short
Spinel comes in red, orange, pink, purple, blue and black. GIA ranks red highest, then a fine cobalt blue, then vibrant hot pink and vivid orange, with violet and lavender lower. A round 1 carat spinel measures about 6.4 mm.
- 8shades on the chart
- 6.4 mm1 carat, round
- 8hardness (Mohs)
Spinel colors
Spinel comes in red, orange, pink, purple, blue and black.
- RedA bright, pure red.
- Hot pinkA vivid pink.
- PinkA softer pink.
- OrangeA vivid orange.
- Cobalt blueA saturated blue.
- LavenderA light violet.
- PurpleA medium purple.
- BlackLooks black face up.
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 spinel color is finest
GIA ranks red highest, then a fine cobalt blue, then vibrant hot pink and vivid orange, with violet and lavender lower. A pure red to slightly purplish red of medium to medium-dark tone is considered the finest of all.
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 spinel color
- Cause of color
- Chromium gives red and pink, and more chromium gives a stronger red. Cobalt gives vibrant blue. Iron and vanadium shift the color toward orange, purple or violet.
- Treatments
- Do not assume spinel is untreated. GIA has documented cobalt and nickel diffusion in natural spinel, heating is also used, and synthetic spinel exists. Ask for a lab report.
- Wear and care
- Spinel is hard enough for everyday wear.
Spinel color and size
Cobalt-blue spinel from Luc Yen, Vietnam is very saturated but small, rarely over 1 carat. Carat is weight, not size. A round 1 carat spinel measures about 6.4 mm, against 6.5 mm for a diamond of the same weight. This table gives the face-up size of a well-cut spinel.
- 0.5 ct
- Round: 5.1 mm
- Oval: 6.3 x 4.3 mm
- Cushion: 4.4 x 4.4 mm
- 1 ct
- Round: 6.4 mm
- Oval: 7.9 x 5.5 mm
- Cushion: 5.6 x 5.6 mm
- 2 ct
- Round: 8.1 mm
- Oval: 10.0 x 6.9 mm
- Cushion: 7.0 x 7.0 mm
- 3 ct
- Round: 9.2 mm
- Oval: 11.5 x 7.9 mm
- Cushion: 8.0 x 8.0 mm
- 5 ct
- Round: 10.9 mm
- Oval: 13.6 x 9.3 mm
- Cushion: 9.5 x 9.5 mm
See the full spinel size chart for every shape, or use the carat to mm calculator for any weight.
Spinel properties
- Hardness (Mohs)
- Value: 8
- Refractive index
- Value: 1.712 to 1.762
- Specific gravity
- Value: 3.58 to 3.61
Close to diamond in density, so the same weight gives almost the same size.
How to compare spinel 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 spinel 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.