NEW YORK, NY.- Diamonds might be a girl's best friend but colored gemstones have become the hottest jewels on the red carpet and in the auction rooms.

Thanks to A-List fans like Angelina Jolie, Beyonce, Naomi Watts, Rosamund Pike and Mila Kunis, rubies, sapphires and emeralds are this year’s must-have gems.

While diamonds will never lose their classic appeal, colored gems are outstripping them in value and proving a canny investment having outstripped other stones in price gains – some having risen by a staggering 2,200 per cent over the past decade.

Now international auction house Bonhams has proclaimed 2015 as the year of the colored gemstones.

In December 2014, Bonhams London sold a pair of Cartier art deco ruby and diamond clip brooches, circa 1930, for an incredible $717,600 on a pre-sale estimate of $120,000 to 180,000.

And a single-stone ring by Van Cleef & Arpels, set with a sugarloaf cabochon Burmese ruby weighing 13.34 carats, sold for $521,400 to a Hong Kong buyer. At $44,000 per carat this broke all ruby price per carat records in London that year.

Experts at Bonhams are expecting the strong market to be reflected at its Fine Jewelry sales in New York and London in April and Hong Kong sale in May.

Susan Abeles, US head of jewelry at Bonhams, said: “Diamonds are classics, but increasingly women want to express their personalities through color. Women are more confident and there is a move to be bolder – even when it comes to engagement rings.

“Women want something truly original, and with a colored stone, where every example is different, they are able to have something unique. Emeralds and rubies are viewed as a bit less formal and reflect the wearer’s personality more than diamonds.

“As ever, fashion is partly celebrity-led and we’re seeing some of the world’s biggest stars wearing colored gemstones on the Red Carpet.”

Bonhams has tracked a significant increase in the price per carat achieved for colored gemstones in its auctions over the last decade.

Susan Abeles said the attraction to collectors and investors was that such stones appeared to be a very safe investment.

She said: “While diamonds are typically seen as the more ‘robust’ area in the gemstone market in terms of seeing a return on investment, figures over the last decade demonstrate that colored stones have actually overtaken diamonds in terms of growth.

“Each gem stone is slightly different so small differences in shade, tone, body color and transparency can have a huge difference in price.

Sapphires on the up: Recent gemstone sales by Bonhams have included a sapphire and diamond ring, set with a cushion-shaped Sri Lankan sapphire weighing 30.08 carats, which sold for $485,700 against a pre-sale estimate of $120,000 to 180,000. Ten years previously, a similar sized ring (29 carat sapphire) sold for $22,000. This equates to a 2,200 per cent increase per carat for large Sri Lankan sapphire stones over the last decade.

Emeralds ones to watch: In November last year (2014), Bonhams Hong Kong sold an important antique cushion-shaped emerald and diamond cluster ring weighing 10.09 carats for $9.3 million.

“Rubies are in most demand and command the strongest prices per carat, followed by Kashmir sapphires and then Burma sapphires and Colombian emeralds.”

In its forthcoming Fine Jewelry sale on April 15 in New York, Bonhams will be auctioning a number of pieces featuring colored stones. Highlighted lots include:

Emeralds
· An emerald and diamond ring estimated at $180,000-220,000. The cut cornered rectangular step-cut emerald, weighing 14.31 carats is flanked with baguette-cut diamond shoulders and mounted in platinum.

Sapphires
· A sapphire and diamond ring centering a cushion mixed-cut sapphire, weighing 17.61 carats, within a circular-cut diamond spray surround and mounted in white gold that is estimated at $200,000-300,000.

· A multicolored sapphire and diamond brooch that is estimated at $40,000 – 60,000. The piece is designed as a vari-cut pink, peach, purple and yellow sapphire spray, and enhanced by vari-cut diamond scroll and trim that measures 3.00 carats.

• A suite of enamel and gem-set and diamond "Turban" jewelry, Donald Claflin, Tiffany & Co. estimated at $15,000 to 25,000. The lot comprises two brooches, each set with a pear-shaped aquamarine or citrine, enhanced by a brown or blue enamel turban, accented with ruby, emerald and sapphire cabochons and circular-cut diamonds. The whimsical piece is accompanied with a pair of earclips of a similar design.

• An unusual floral gem-set and enamel compact by Cartier, Italy with beautiful gold work that is estimated at $15,000 – 20,000. The oval compact is made of fine 18K yellow gold, and is embellished with a textured gold petal motif that is enhanced with blue and green enamel florets, an emerald, a sapphire and turquoise cabochons, with circular-cut diamond detail.

Rubies
· An important suite of diamond and ruby jewelry, Van Cleef & Arpels, 1988, which is estimated at $180,000 – 220,000. This suite is a splendid example of Van Cleef & Arpel's romantic and luxurious vintage designs set with superbly matched calibré set cut rubies and diamonds.

And not forgetting diamonds….

· A fancy vivid yellow oval brilliant-cut diamond ring, estimated at $220,000 – 280,000. The glittering yellow diamond weighs 6.64 carats and is flanked by fancy-cut diamonds and mounted in 18k white and yellow gold.

· A pair of colored diamond ear studs made by Graff that is expected to fetch between $80,000 and $100,000. The beautiful earrings are each set with a cut-cornered rectangular modified brilliant-cut fancy light yellow diamond, weighing 5.03 and 5.19 carats.

As well as the major stones, rarer varieties have also become highly sought-after. These include:

· Padparadscha sapphires: Extremely rare and a pretty orange pink color. The name derives from the Sanskrit word ‘Padma ranga’, referring to the delicate color of the lotus flower.

· Spinel: the 170 carat l bead in the Imperial State Crown of the British Crown jewels is often referred to as the ‘Black Prince’s Ruby’, but it is in fact a red spinel. It is one of the oldest components of the Crown Jewels with a history going back to the 14th century. Historically many red stones are given the generic term ruby – including many spinels. An example of a beautiful art deco spinel ring, weighing 18.70 carats was sold by Bonhams in London in April 2012 for $73,300.

· Imperial Topaz: Topaz occurs in a variety of hues from colorless, blue, orange, pink and brown. By far the most valuable is the golden or rare pink Imperial Topaz which is mainly found in one location, the Ouro Preto district of Brazil. In December 2011, Bonhams sold a19th century pink topaz brooch, weighing approximately 19.00 carats, for $48,300.

· Pariba tourmaline: Extremely rare and fine with examples selling for hundreds of thousands of pounds per carat.

Susan Abeles added: “In many cases, we are seeing items coming onto the market that have been worn and loved but have now been passed onto the younger generation.

“There are also some owners who simply do not know what they have got in the back of their jewelry box, so we’d encourage people to dig out pieces they might not have worn for years and bring them in for valuation – they may have appreciated quite dramatically in value without their knowledge.”

The increase in prices has been a gradual and steady rise.

Private buyers and in particular Asian buyers have pushed up the price of faceted stones in the last 10 years. However, in the last five years, Chinese dealers have also been going to the source to buy from mines direct which has pushed up prices.

Original stones from old mines are the rarest and most sought after. They are very hard to find now which is why they command such high prices.