Blue, green, teal and turquoise

bright teal, green, yellow, blue gemstone, cut in the shape of a boat called navette or marquise, held in jeweller's claws

Blue and green are probably the most subjectively variable colours on the visible light spectrum. Last week a friend shared this quiz with me called, Is my Blue Your Blue which compares your perception of blues and greens against others. In particular it will help you know if you see the enigmatic colour turquoise as being ‘more blue’ or ‘more green’.

I thought this would be a fun thing to do seeing as it is September and through and through it’s the month of sapphire. Sapphire is the sister of ruby, she holds all of the colours of the rainbow apart from the reds we reserve for ruby. A variety of the mineral corundum–aluminium oxide–sapphire rates as the second hardest crystalline mineral at 9 on the Mohs scale of hardness, second only to diamond at 10. As well as a stunning array of colours and gradients when cut as gemstones, synthetic corundum or sapphire is used industrially to make hard, transparent materials such as covers for watch cases. Synthetic sapphire is also a workhorse for composite gemstones simulating others such as corundum-corundum doublets.

Is my blue your blue?

Well my turquoise is blue. I did it twice. Most of my relatives’ turquoise is green. I think it varies according to the time of day you do the test, your screen, the lighting around you, and the make up of rods and cones in your eyes which perceive and process colour. It’s also a digitally-generated colour which isn’t quite the same as gazing into a gemstone. I am eternally drawn to the effect and uses of colour and have written about the psychology of colour when curating.

Do the Is my blue your blue quiz. What did you get?

Rough sapphire crystal showing hexagonal colour-zoning including how blue goes into greenish-yellow (Tehmina Goskar).

Teal – a sapphire fad?

Earlier this month I had the absolute pleasure and delight of attending the Jewellery Valuers Association annual conference in Loughborough. At one of the workshops a gem dealer commented that he felt the recent interest in teal sapphires was a fad that will soon end. This got me thinking about colour, preference and how they change with how gemstones are named and marketed and the fashions which follow. While there remains an idea that the best quality sapphires are velvety blue, either of a cornflower hue or a violetish royal blue, plus if that colour is matched by a place designator such as ‘Kashmir’ or ‘Sri Lanka’ those stones will remain, long-term, the preference of connoisseurs and investors.

bluish-greenish gemstone shaped as a boat called marquise or navette
No-heat parti-colour sapphire from Australia, custom cut, marquise cut, over 3ct (Tehmina Goskar).

So what of teal sapphires? Teal, like turquoise is a subjective colour that will combine greenish to yellowish tones with blue. Many of the best quality teal sapphires have emerged from Australian mines, like this stunning no-heat 3ct, precision-cut nanette or marquise, parti-colour sapphire which has your classic sapphire blue, going into turquoise (brighter greenish-blue), going into teal (darker yellowish-greenish-blue). I can’t stop looking at it. And the blues, yellows and greens change with different intensities of daylight and artificial light. The high polish also gives each colour space to pop as you turn the stone and each secondary and tertiary shade that makes up the overall effect of the parti-coloured stone provides for a kaleidoscope effect.

It is true that many poorer quality sapphires are being marketed as teal to follow this trend but whereas the greenish tinges to traditional blue sapphires used to be considered of lesser quality (also because green is a more abundant (cheaper) colour for natural corundum sapphire) it would be disingenuous to suggest that people are somehow being duped into thinking teal is a better colour than it actually is. We all know what we like, and we should also choose the colours of things that we adore, not just what we’re told to love.

1 comment

  1. Interesting point about colour perceptions. Most of us have a favourite colour, so that would also influence us when selecting gems and often the attraction is quite immediate. The point you have made about other factors influencing the colour we see, of the gem we like, such as ambient light, is quite useful when selecting a gemstone or jewel. Thanks for sharing the blue/green link!

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