10 awesome blue gems that can chase your Monday blues away

A sky blue variety of the beryl mineral species, aquamarines are a lesser saturated blue gem that needs no introduction. Thought to be a gem created by the sea and carries the ability to calm oceans, it is now a popular gem choice for customised and sometimes high-end jewellery.

What causes aquamarine’s attractive colour is mainly due to the trace element of iron. Like all gems, the more trace elements, the more vivid the colour it gets. For aquamarine, its blue saturation largely lingers around the lower range of the colour tone, which contributes to its sky blue colour. Despite that, most natural aquamarines occur with a slight tint of green, due to different oxidation states of iron within the crystal lattice of the crystal. Therefore, to create pure blue hue, the majority of aquamarines in the market are exposed to heat treatment with the sole purpose of removing the green tint. With that it allows them to show the sky blue it is known for. Heat treatment on aquamarine is generally accepted in the trade even without disclosure.

Although aquamarine has a lower colour saturation compared to sapphire, it does have a wide tone range from pale blue to Santa Maria blue - a deeply saturated blue colour. Generally blessed with superior clarity, clear to the eye specimens are quite easily attainable.

Summary of common localities of aquamarine: Brazil, Santa Maria (USA), Myanmar, Sri Lanka, Pakistan, Afghanistan, Queensland (Australia), China, India, Kenya, Madagascar, Mozambique, Namibia, Nigeria, Zambia, Zimbabwe.

Here are some rough aquamarines from various parts of the world, Brazil, Pakistan, Myanmar.	A 6.19ct baguette cut aquamarine getting ready to be set into a piece of jewellery. Heated aquamarines tend to show a ‘purer’ blue colour as compared to the unheated ones, which tend to show a shade of green with the blue.	An approximately 20 carat size aquamarine set as a pendant. Due to its clarity and size, aquamarine are often used as the main gem in a large piece of jewellery. Clean and large sized aquamarines are sometimes hard to come by.	A 20 carat pear-shaped Madagascan aquamarine with a Santa Maria colour. Notice the deep blue colour as compared to the aquamarine in the previous two pictures.

Tourmalines are known to be available in a wide variety of colours. There are two blue varieties namely Indicolite, and the rare Paraiba.

Indicolite is more common.. Its colour usually leans towards a darker tone of blue, mainly due to the colour agent of iron which also causes it to be dark. On the bright side, indicolite has superior clarity.

Paraiba on the other hand, is the rarest variety of the tourmaline group. Originally discovered in the late 1980s in Brazil, it was soon also uncovered in Nigeria and Mozambique in very limited quantities. Its colour is unlike any other. Coloured by traces of copper or manganese comes a uniquely neon blue or green that is unforgettable. This amazing hue can easily compensate for the eye-visible inclusions which can be common in paraibas. A good quality cut that highlights its natural brilliance and scintillation improves its value exponentially. In the paraiba market, heat-treatment is very common. It helps turn those non-neon-copper/manganese-bearing tourmalines into paraibas, this increases their supply in the market. Currently, identifying heat treated paraibas proves to be more difficult than expected, if just by using standard equipment. Thus, it would be best to assume the paraiba is heated unless stated otherwise.

Summary of common localities of tourmalines: Minas Gerais, Pariba (Brazil), Sri Lanka, Myanmar, Mozambique, Vietnam, California, Maine (USA), Madagascar, India, Pakistan, Nigeria, Namibia, France, Tanzania, Italy

A box of tourmalines with its variety of different colours.	Unheated paraiba tourmaline in the box.	Indicolite

A 1.49ct baguette cut indicolite	A 3.06ct indicolite that has a tinge of green that almost makes it look like a paraiba tourmaline	A paraiba crystal specimen in matrix and one lot of faceted unheated paraiba tourmalines from Brazil.

Considered a modern gem, this blue gem burst into the market by storm after it was discovered in 1967, with the help of Tiffany & Co. As blue as a sapphire, tanzanite is found in only one place in the world, the Merelani Hills in Tanzania. On top of its vivid colour, tanzanite possesses excellent clarity which helps boost its popularity in the jewellery industry. Consumers are attracted by its unique colouration and choose to overlook that it has a lower hardness than most popular gemstones at 6.5 and a perfect cleavage in one direction.

What makes tanzanite unique is its eye-visible trichroism, making it shift into three different colours - blue, purple, and brown/red, when viewed from different axes of the gem. It proves to be an extra challenge for lapidarists due to this optical property as they have to properly orient the gem during cutting so as to showcase a specific colour. The demand for blue gemstones remains strong and as such, the choice of colour to highlight while cutting tends to slant towards blue.

Tanzanite is a gemstone commonly subjected to heating. Heating primarily removes unfavourable brown/red colour in a tanzanite gem, permanently converting the stone to a dichroic gem, while increasing its hue saturation in the process. It allows consumers to enjoy the vivid blue or purple without having any interference by the brown/red.

Summary of locality: Tanzania (Africa)

A custom-designed 1.66carat pear-shaped tanzanite set with diamonds and pink sapphires in an 18k unplated white gold ring.

A magnesium aluminium oxide, this gem is fast gaining momentum in its value. Hard, refractive, and colourful, spinel can be utilised in jewellery for its relatively clean clarity, and also collected as a mineral specimen for its symmetrical octahedral crystal habit.

Blue spinel has a lesser exposure in the market when compared to red spinel, which is considered to be an alternative to ruby. The blue spinel can be substituted for a blue sapphire. It is coloured by the element of iron in most cases creating deep dark tones of blue.

Another example of spinel’s fast track to stardom, is the discovery of the “cornflower” type blue spinel. In the early 2000s, it was unearthed in Luc Yen, a rural district in Yen Bai, Vietnam. For so long, it is the only source for cobalt-coloured spinel, and that propelled this bright blue gem into one of the rarest gemstones. Moreover, gem-quality cobalt specimens are ridiculously scarce, so rare even a fairly clean 0.50ct is considered a novelty.

Summary of common localities of spinel: Sri Lanka, Myanmar, Vietnam, Africa, Cambodia, Brazil, Madagascar, Nepal, Nigeria, Tadzhikistan, Tanzania, Thailand, New Jersey (USA), Australia.

A 1.32 carat blue spinel. This blue spinel may come in a range of greyish blue to greenish blue and purplish blue. The blue colour is caused mainly by iron	Shown here is a 3.01carat gahnospinel. This is a species of gem that is between spinel and gahnite (also known as zinc spinel) in composition, coloured by iron	This photo taken under the microscope at about 20x magnification shows a natural fingerprint inclusion in the gahnospinel	Vernueil Flame Fusion synthetic blue spinel, rough and 0.72ct faceted synthetic blue spinel coloured by cobalt