“Teal” occupies a region between blue and green, but it has no universally fixed boundary in the gemstone trade. Colour descriptions are useful for comparison; the individual stone remains the standard.
Hue
Hue is the basic colour family perceived. A teal sapphire contains blue and green, but one may dominate. A blue-dominant teal often reads as blue first with a green modifier; balanced teal gives both similar visual weight; green-dominant teal reads green first with a blue modifier.
Tone
Tone is relative lightness or darkness. Light teal can feel airy but may have less apparent colour strength. Medium tones can allow both colour and brilliance to remain apparent. Deep teal may be dramatic, but if the tone becomes too dark it can look nearly black in weak light. Labels such as light, medium and dark are comparative, not laboratory grades.
Saturation
Saturation describes the intensity of colour. Weak saturation may appear greyish; moderate saturation can look subtle and nuanced; strong saturation can look vivid. Strong saturation is not automatically best if tone is too dark or the cut prevents light return.
Blue-dominant teal
A blue first impression with a visible green component. Metal colour and lighting can change the balance perceived.
Balanced teal
Blue and green carry similar visual weight. There is no instrument-defined point at which a stone becomes perfectly balanced.
Green-dominant teal
Green is primary, with enough blue to keep the overall impression within the teal family.
Colour zoning
As sapphire grows, changes in trace-element availability can create bands or areas of differing colour. Zoning may look like stripes, angular bands or separate patches. A cutter can orient and place zones to blend them face-up, to showcase them, or occasionally to conceal less attractive distribution.
Judge zoning face-up and while gently rocking the stone. Deliberate, harmonious zoning can be a feature; uneven zoning that leaves distracting pale or dark areas may reduce appeal for another buyer.
Parti sapphires
A parti sapphire displays distinct colour partitions or zones, often blue with green or yellow. A parti sapphire can have an overall teal impression, but not every parti sapphire is teal. Likewise, a relatively even teal sapphire need not be described as parti. The words answer different questions: teal describes colour impression; parti describes visible colour distribution.
Lighting and screens
Daylight, warm domestic lamps and cool LEDs have different spectral output. A stone can look greener or bluer as the light changes. Camera white balance, exposure, image processing and screen calibration add more variables. Ask for several accurate views and, where practical, see the stone in your normal lighting during the return period.
Which teal colour is most valuable?
No single teal colour is universally most valuable. Desirable combinations shift with individual taste and market demand. Colour attractiveness, saturation, tone, clarity, cut, size, treatment, documented origin and overall beauty can all affect price. A well-cut, lively green-teal may be preferred over a darker “balanced” teal, or vice versa.
Next, learn how origin should—and should not—be interpreted, or use the UK buying guide to compare stones.