Six of the best gemstones to invest in

If you're looking to invest in a piece of gemstone jewellery but don't have deep pockets, don't worry! As our list shows, the big four – diamonds, rubies, emeralds and sapphires – may still dominate as the top investments but humbler stones, such as tourmaline and tanzanite are rising in value, too.

The value of a particular gemstone is determined by various factors, often referred to as the 'four Cs': colour, clarity, cut and carat (weight). Exceptional colour saturation, rarity and larger sizes generally command higher prices in the market. Additionally, demand and trends for particular gemstones can influence price. 


Tourmaline is a fascinating gemstone that occurs in a wide range of colours, making it highly sought-after. The different kinds of tourmaline are prized for their unique characteristics and colours, each contributing to their individual worth. The rarity, size, clarity and quality of the gemstone also impact its value. 

Paraiba tourmaline

Renowned for its vivid and intense neon-blue or green colours, Paraiba tourmaline is one of the most sought-after gemstones in the world. The neon-blue variety is the most rare and valuable, and green less so. Originally discovered in Paraiba, Brazil, in 1989, only five mines in the world produce this gemstone – three in Brazil and two in Africa. Paraiba tourmaline can fetch up to US$50,000 per carat.

Rubellite tourmaline

This stunning tourmaline displays a deep red to purplish-red hue. It is the deeper red or raspberry tones – those resembling rubies – that are the most sought-after. Rubellite tourmaline is worth US$1,000 per carat or more.

Watermelon tourmaline

As the name suggests, this gemstone is renowned for its distinctive colour zoning resembling the cross-section of a watermelon. The value of watermelon tourmaline is influenced by the intensity and contrast of the colour zoning of the green on the outer edge, transitioning into a pink or red centre, as well as the overall clarity and size. Watermelon tourmaline averages between US$3 and US$8 per carat, but large stones can demand between US$500 to US$600 per carat.

Chrome tourmaline

Chrome tourmaline is prized for its vibrant green hue, often with hints of emerald-like brilliance, which is derived from the presence of chromium. The more intense and pure in colour the stone is, the higher the price it can command. Chrome tourmaline sells for US$800 per carat or more.

Indicolite tourmaline

Indicolite tourmaline exhibits shades of blue, ranging from light to dark and from greenish-blue to deep blue. Vivid and saturated blue tones are particularly prized. Indicolite tourmaline can reach prices of US$1,000 per carat and above. 

Pink Diamond

Pink diamonds are among the rarest and most valuable gemstones in the world, with the best quality ones commanding 20 times the price of their white counterparts. Their captivating beauty and scarcity contribute to their high worth. Pink diamonds are graded based on their colour intensity, with stronger and more vibrant hues commanding higher prices. The rarity of pink diamonds is attributed to the unique geological conditions required for their formation. These precious gemstones are found in only a few select mines worldwide, and were primarily sourced at Australia's Argyle Diamond Mine until it closed in 2020. However, the famous Pink Star diamond, weighing 59.6 carats, was mined by De Beers in South Africa in 1999, and cut from a 132.5 rough diamond. It became the world's most expensive gemstone when it sold in 2017 for US$71.2million. Due to their rarity and the increasing demand from collectors and investors, pink diamonds have become highly sought-after and coveted by gemstone connoisseurs and jewellery enthusiasts. The cost of a pink diamond starts at US$10,000 per carat.


Tanzanite, a stunning blue-violet gemstone, has been rising in value due to a combination of factors. First and foremost, tanzanite is found exclusively in Tanzania, where mining challenges make it a rare and limited resource. It is 1,000 times more rare than diamond. Additionally, its vibrant colour make it highly desirable among gemstone enthusiasts. The gemstone's appeal is further enhanced by its pleochroic nature, displaying different colours when viewed from different angles. Tanzanite's rising popularity, coupled with its limited supply, have led to it becoming much sought-after, appreciated both for its beauty and investment potential. Tanzanite ranges between US$100 to US$800 per carat, with the deeper the colour and bigger the size, the higher the value.

Colombian Emerald

Colombian emeralds, renowned for their exceptional quality and captivating green colour, are regarded as among the rarest and most valuable emeralds in the world – particularly those coming from the Muzo mine. The rich geology and unique natural processes in this region creates emeralds of extraordinary beauty. The scarcity of these finest-quality Colombian emeralds has even resulted in a higher market value compared to diamonds of comparable size and quality. An emerald that receives a 'Natural AAA' grading will be a rich in colour and exhibit very high brilliance, and an emerald that shows high clarity will steeply increase in value. Colombian emeralds can cost up to US$100,000 per carat.

Kashmir Sapphire

Sapphires from Kashmir, a region in the Himalayas, hold legendary status in the world of gemstones. Revered for their exceptional beauty and rarity, Kashmir sapphires are highly sought-after by collectors and connoisseurs. Known for their mesmerising velvety-blue colour, often described as 'cornflower blue', Kashmir sapphires possess a unique combination of rich hue, unparalleled saturation and subtle silky appearance. The sapphire deposits were discovered in 1881 in the Zanskar Range of the Himalayas following a landslide. Mining began in 1882 and continued until 1887 when the mine was depleted. Since most Kashmir sapphires were mined during this brief period and only a handful of high-quality stones over five carats exist in the world, this ensures they'll always be increasing in value. Kashmir Sapphires can command US$60,000 per carat.

Burmese Ruby

Rubies from notable sources like Burma (Myanmar) and Mozambique are highly sought-after due to their historical reputation for producing exceptional gems. The most prized rubies exhibit a deep-red colour, often referred to as 'pigeon's blood' red, with excellent saturation and minimal undertones. The world's most expensive ruby is called the Sunrise Ruby. It weighs 25 carats and was sold for US$30million, making it the most valuable coloured gemstone in the world (this category does not include coloured diamonds, which have sold for higher prices). Coloured rubies, also known as fancy or fancy-coloured rubies, are exceedingly rare and highly coveted for their unique hues. These rare rubies can exhibit colours such as pink, purple, orange and even vibrant blue or green. The value of coloured rubies is determined by the intensity and saturation of their unique hues, with deeper and more vivid colours commanding higher prices. These exceptional gemstones are always in demand from collectors and investors alike. Burmese rubies cost around US$10,000 per carat. 

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