Teal Sapphire vs Blue Sapphire Engagement Rings: Colour, Origin and Price

Teal sapphire vs blue sapphire: what is the difference?

Teal and blue sapphires are both corundum, which is crystalline aluminium oxide (Al₂O₃). Pure corundum is colourless. Tiny traces of other elements, measured in parts per million, give it colour. In blue sapphire, iron and titanium sitting next to each other in the crystal absorb red and yellow light, so the stone looks blue. Teal sapphire has the same iron–titanium pair plus extra iron on its own, which adds a yellow component. Blue plus yellow reads as green, and the blend of blue and green is what the trade calls teal. Our complete sapphire gemstone guide covers the whole family, from blue to pink to colourless.

So when you compare teal sapphire vs blue sapphire, you are not comparing two different gems. Hardness, toughness, refractive index and density are identical. What changes is the colour, how that colour behaves in different light, where the stones are usually mined, how often they are treated and what they cost. If you have already settled on teal, our teal sapphire engagement ring designs page goes further into styles; to see sapphire beside other coloured stones, start with our overview of coloured gemstones and birthstones.

• Blue sapphire: one clear hue, from light cornflower blue to deep royal blue. The classic, most recognised sapphire colour.
• Teal sapphire: blue and green together in one stone, often with a visible shift between the two as the stone moves.
• Both: 9 on the Mohs scale, excellent toughness, and well suited to an engagement ring worn every day.

What colour is a teal sapphire, and how is it graded?

Teal is a trade term, not a grading category. GIA and other laboratories describe colour with hue words such as greenish blue, bluish green or blue-green, so you will rarely see the word teal on a report. In the trade, a sapphire is generally called teal when blue and green are both clearly present, anywhere from mostly blue with a strong green note through to an even split and on to mostly green with a strong blue note. Push further towards green and it becomes a green sapphire; push further towards blue and most people would simply call it a greenish blue sapphire.

Gemmologists describe any colour with three words. Hue is the basic colour (blue, green, teal). Tone is how light or dark it is, from very light to very dark. Saturation is how strong the colour is, from greyish to vivid. Blue sapphire is valued most for a pure blue hue, a medium to medium-dark tone and strong saturation. Too dark and it looks inky, almost black at night; too light and it looks washed out. Teal is judged more on personal taste, but the same faults apply: greyness makes a teal look slate-like and dull, and very dark tone hides the green. Each of these terms is also defined in our plain-English jewellery glossary.

Some sapphires show separate zones of colour, for example a blue band beside a green or yellow one, rather than an even blend. Those are usually sold as parti sapphires, from the word particoloured. The difference is simple: teal is a mixed colour, parti is colours side by side. Our guide to parti sapphires with two or three colours in one stone shows how they look set in a ring.

How do gemmologists tell teal and blue sapphire apart?

The key is pleochroism, a property of coloured, doubly refractive gems in which light travelling in different directions through the crystal picks up different colours. Corundum is dichroic, meaning it shows two colours. In blue sapphire the two are usually violetish blue and greenish blue, close enough that you barely notice. In teal sapphire they can be quite different: a clear blue looking down one direction of the crystal and green to yellowish green along the other. A skilled cutter orients the rough so the table (the large flat top facet) faces the preferred colour, but in a teal you often still see flashes of both blue and green as you tilt it. Many people love that movement; others find it unsettled.

At the bench, a Graduate Gemologist (GIA) uses a few simple instruments to confirm what a stone is and how it formed:

• Refractometer: sapphire reads about 1.762–1.770, with a birefringence (the gap between its two readings) of about 0.008–0.010. Teal and blue give the same numbers, which confirms both are corundum.
• Dichroscope: a small viewer that shows the two pleochroic colours side by side, which makes the blue and green in a teal obvious.
• Spectroscope: iron-rich sapphires, including most Australian stones and many teals, show a strong absorption line near 450 nm.
• Microscope: natural sapphires show silk (fine rutile needles), fingerprints (healed fractures), small crystals and straight or hexagonal colour zoning. Lab-created sapphire grown by flame fusion shows curved growth lines and gas bubbles instead.

Because teal sits between two hues, lighting changes the balance more than it does in blue. Under warm indoor light, which carries more yellow, a teal tends to lean green; in daylight or cool LED light it usually leans blue. Blue sapphire shifts less, though some lean slightly violet in warm light. This is not the same as a true colour-change sapphire, which switches between clearly different hues such as blue and purple. If blue is your direction, our checklist for judging blue sapphire quality covers tone, saturation, windowing and extinction in detail.

Where do teal and blue sapphires come from, including Australia?

Australia is an important source of both colours. Australian sapphires are found in gravels washed out of old basalt volcanoes, mainly in the New England region of New South Wales around Inverell and Glen Innes, and on the Anakie gemfields of central Queensland around Rubyvale, Sapphire and Anakie. Basalt-related sapphires are rich in iron, which is why Australian stones run to deep blue, green, yellow, parti and teal. In the 1970s and 1980s Australia supplied a large share of the world's commercial blue sapphire, though much of it was cut overseas and sold without its origin. Our page on engagement rings set with Australian-mined sapphire looks at the fields in more depth.

Origin can affect price, especially for blue. Names such as Kashmir, Burma and Ceylon carry a premium, and our guide to what Sri Lankan Ceylon origin really tells you explains why. Origin cannot be judged by eye, though. It takes laboratory analysis of inclusions and trace elements, and even then some reports give only an opinion. For teal, origin matters much less to price than colour does. Our view across the counter: judge the stone in front of you, not the name on the label.

Are teal and blue sapphires durable enough for an engagement ring?

Yes, and equally so. Both rate 9 on the Mohs scale, the scale of scratch resistance from 1 (talc) to 10 (diamond). That puts sapphire well above household dust, which contains quartz at 7 and slowly dulls softer gems. Sapphire's toughness, its resistance to chipping and breaking, is rated excellent because corundum has no cleavage (no natural plane along which it splits cleanly). A hard knock can still chip a corner or a thin edge, and inclusions that reach the surface weaken a stone, but for everyday wear sapphire is one of the most practical coloured gems you can choose.

If you are weighing sapphire against other centre stones, our comparisons of diamond and sapphire engagement rings and emerald versus sapphire for everyday wear go through the trade-offs in colour, sparkle and durability. The short version: sapphire and ruby, both corundum, are the hardest and among the toughest coloured options for an engagement ring.

Are teal and blue sapphires heat treated?

Most blue sapphires on the market have been heated, typically to somewhere between about 1,200 and 1,800 °C. Heat can dissolve silk, even out colour and lighten stones that are too dark, which is especially common for iron-rich Australian blues. Heating alone is permanent, stable and widely accepted in the trade, but it must be disclosed, and a fine unheated blue sells for considerably more than a heated stone of the same look.

Teal is a little different. Because the blend of blue and green is the look people want, many teal sapphires are sold unheated; heating can push the colour towards blue or lighten it, and there is less reason to change it. That is a tendency, not a rule: plenty of teals are heated too, so always check the report rather than assuming.

• Beryllium (lattice) diffusion: beryllium is diffused into the crystal at high heat. Mostly used for orange, yellow, pink and padparadscha-like pink-orange colours, occasionally for blue. Lower value than heat alone.
• Surface diffusion: titanium diffused into a thin outer layer to create blue. The colour can be polished away if the stone is ever recut or badly chipped.
• Glass filling: fractures filled with glass to improve clarity. Far more common in ruby, but seen in some low-cost sapphire. Fragile, and much lower value.

Ask for an independent report that states either no indications of heating or indications of heating, and whether any other treatment was detected. Under the microscope, a gemmologist looks for altered or broken-up silk and small discoid fractures with glassy halos, both signs a stone has been heated.

Teal sapphire vs blue sapphire price: which costs more in Australia?

For stones of similar size, clarity and cut, a fine blue sapphire usually costs more per carat than a teal. Blue has the longest history and the strongest demand, and the most saturated royal and cornflower blues are scarce. Teal has grown in popularity over the past decade, but its price per carat generally still sits below a comparable fine blue, and you can often find a lively, unheated teal for the price of a heated commercial blue.

These are broad ranges only and move with the market, the exact colour and the report. Colour drives sapphire price more than anything else, followed by size, treatment, clarity and cut. Lab-created sapphire is real corundum, with the same hardness and refractive index, but it is grown in a laboratory rather than mined, costs a small fraction of natural, and must always be sold as lab-created or synthetic. Other fancy colours, such as purple sapphire and warm orange sapphire, also usually cost less than a fine blue of the same size.

Which metal and setting suit a teal or blue sapphire engagement ring?

Metal colour reflects up through a gem and changes how it looks. A blue sapphire looks crisp and cool in platinum or white gold; in yellow gold it reads as classic and rich, though a dark blue can look deeper still. A teal sapphire is more flexible: yellow or rose gold warms it and brings out the green, while white gold or platinum pulls it towards blue. If you love the green side of your teal, warm metal; if you love the blue side, white metal.

• Four or six claws: let the most light into the stone, which helps darker blues and teals stay bright.
• Bezel: a rim of metal around the edge. Very secure and protects corners, but it can make a dark stone look darker, so it suits medium tones better.
• Halo: a ring of small diamonds around the centre adds sparkle and makes the sapphire look larger.
• Three-stone: diamonds or colourless white sapphire side stones either side of the centre.
• Open gallery: an open space under the stone lets light in from the side and stops dirt building up behind it.

Sapphire is denser than diamond, with a specific gravity of about 4.00 against diamond's 3.52, so a 1 carat sapphire looks smaller than a 1 carat diamond. A 1 ct round sapphire is typically about 6.0 mm across compared with about 6.5 mm for a round diamond, and a 1 ct oval sapphire is often around 7 × 5 mm. Compare millimetres, not just carats. For finished designs and ideas, see our sapphire engagement rings made in Melbourne.

How do you choose between a teal and blue sapphire? Step by step

1. Decide on the colour you want. Look at real stones side by side, not just photos, which often exaggerate saturation and hide greyness.
2. Check the stone in three lights. Daylight, warm indoor light and a torch. A teal will shift more than a blue; make sure you like every version.
3. Tilt it slowly. Watch for pleochroic flashes in a teal and for dark, dead areas (extinction) or a see-through centre (windowing) in either colour.
4. Read the report. Confirm corundum, natural or lab-created, any heating or other treatment, and the measurements in millimetres.
5. Check clarity where it matters. Fine silk is normal; avoid fractures or cavities that reach the surface, especially near corners.
6. Match the metal. Hold the stone against white and yellow metal to see which side of its colour you prefer.
7. Choose a setting that protects it. Claws or a bezel at any corners, and an open gallery so light and cleaning water can reach the back.