Are diamonds no longer a consumer’s best friend?

Are diamonds being downgraded by consumers?

Diamonds, long sought-after and the ultimate sign of luxury, are facing increased pressure from rival gemstones, according to one retailer.

Vashi Dominguez, the founder, CEO and chairman of Vashi, which sells diamonds and jewellery directly to the public, told CNBC that there was a resurgence in interest from consumers for emeralds, rubies and sapphires.

The value of emeralds has soared over 1,000 percent in the last three years while rubies have seen their price shoot up over 60 percent since 2005.

(Read more: Investing in diamonds? Good luck getting prices)

"Diamonds have always been a girl's best friend and they are getting increasing competition for gemstones now and the reason for this is just women," Dominguez told CNBC. "Women are driving up the market and pushing the price of gemstones to go up and up and up."

Dominguez said that the increased interest in other gemstones was down to the fact that the production of emeralds, rubies and sapphires had begun to drastically improve in recent years.

"The market has generally been driven by small independent producers, therefore consistency and reliability has always been a challenge," he said. "But there are a number of companies now that are working very hard in integrating resources and expertise to be able to get a consistent supply of ethically-sourced premium quality gemstones."

(Read more: All that glitters: Diamonds outshine gold for Chinese brides)

Vashi did emphasize that diamonds were not being "downgraded" by consumers, and it is evident that diamonds still maintain a large popularity. For example, China's diamond market, now the world's second largest after the U.S., has more than tripled to $22.8 billion over the last five years, according to data from market research firm Euromonitor.

Furthermore, the "Pink Star", a huge flawless pink diamond, sold for 76.3 million Swiss francs ($83.02 million) including commission fees in Geneva in November, a world record price for a gemstone at auction, according to Sotheby's.

(Read more: 'Pink Star' diamond sells for world record $83 million)