Last updated on November 23, 2022
At first sight, aquamarine and paraiba tourmaline are similar-looking gemstones. Both have soft blue to greenish-blue colours; however, the range of their hues and other properties is different. Aquamarine vs paraiba tourmaline – let’s discover the difference and learn not to confuse the two.
Aquamarine vs Paraiba Tourmaline Formation
Aquamarine is the light blue to the deep dark blue and greenish-blue variety of beryl mineral group. It has been used in jewellery for thousands of years with references in Roman, Greek, Egyptian and Sumerian writings.
Like other beryl family gemstones, aquamarine formed within pegmatites under heat and pressure for hundreds of millions of years. Pegmatites are formed during the final stage of magma crystallisation. When magma under the earth’s crust interacts with mineral-rich rocks, they heat up and form gemstones. Pure beryl is colourless; however, if it interacts with minute quantities of iron, colourless gemstone turns into enchanting blue and produces aquamarine.
Paraiba tourmaline is a brightly coloured copper-bearing elbaite that shows a range of blues and greens. It is a relatively recent discovery in the gemstone world; however, since its introduction in the late 1980s, paraiba tourmaline has become a highly sought-after gem among jewellers and collectors.
Similar to aquamarine and other elbaites, paraiba tourmaline was formed in pegmatites. However, its crystals formed under very unusual conditions with large amounts of trace elements of copper and manganese. This phenomenon is unique because copper is not a colouring agent in any other tourmaline variety, and normally colouring in tourmalines is caused by iron, manganese, chrome and vanadium.
Aquamarine vs Paraiba Tourmaline Colour and Clarity
Both aquamarine and paraiba tourmaline have blue and greenish-blue colours. However, there are several distinctions in their colour, hue and intensity, which help us set paraiba and aquamarine apart.
Aquamarine gets its colour from the presence of iron microelements in pure beryl, while paraiba tourmaline is coloured by large amounts of trace elements of copper and manganese in its crystal structure. This difference causes paraiba tourmaline to have an unusual blue-green colour glowing with neon. In addition, paraiba tourmaline shows slightly more saturated shades.
It is worth mentioning that both aquamarine and paraiba tourmaline may receive heat treatment. In the case of aquamarine, treatment is used to lighten darker colours and to change less popular colours into blues, while paraiba is treated to give it a more pure blue colour, as pure blue gems are more valuable.
The clarity in paraiba tourmaline is tolerated more than in aquamarine. Eye-visible inclusions in paraiba are not considered negative features, while high clarity in aquamarine is part of its charm, and almost all aquamarine available on the market is eye-clean.
Aquamarine vs Paraiba Tourmaline Durability and Rarity
Aquamarine is a durable gemstone with a rank of 7.5 to 8 on the Mohs scale of hardness. In comparison, paraiba tourmaline is a less durable gem, with a rank of 7 to 7.5 on the Mohs scale. Both gemstones are scratch-resistant; however, the difference in durability is quite an important factor that can help a professional tell between the two.
Also, both aquamarine and paraiba are sensitive to direct sunlight. Meaning, that if exposed to the sun for a too long period, the colour of the gem can significantly fade, and this cannot be reversed. The same is true for prolonged exposure to heat.
In terms of rarity, paraiba tourmaline is the winner. It is mined only in three countries – Brazil, Mozambique and Nigeria. In comparison, aquamarine is more abundant and can be found worldwide, with the largest deposits in the Minas Gerais mines of Brazil. Other aquamarine deposits are located in China, Kenya, Madagascar, Mozambique, Myanmar, Nigeria, Pakistan, Russia, Ukraine, the United States and Zambia. This also makes aquamarine more affordable than paraiba tourmaline in comparison to the cost per carat.
Aquamarine vs Paraiba Tourmaline Properties
|Crystal System||Hexagonal||Hexagonal (trigonal)|
|Colours||Light-blue to deep dark blue, greenish-blue and green-blue||Greenish-blue, bluish-green, green, blue, neon blue, violet, purple and pink|
|Hardness||7.5 - 8 on the Mohs scale||7 - 7.5 on the Mohs scale|
|Refractive Index||1.564 - 1.596||1.61 - 1.67|
|Specific Gravity||2.72 (+0.18,-0.5)||2.8 - 3.3|
|Transparency||Transparent to opaque||Translucent to transparent|
|Birefringence||0.005 - 0.009||0.013 0.024|
|Lustre||Vitreous||Vitreous to resinous|
|Cleavage||Imperfect, basal, almost never seen||None|
Featured image: aquamarine - Minakryn Ruslan / Canva, paraiba tourmaline - Sebaistian Layser / Canva. A derivative work by Diamond Buzz.