Gembridge appoints gem dealer, specialist in opal and sapphire, as Australia ambassador


Digital coloured gemstone trading platform Gembridge has appointed Mark Tremonti, a groundbreaking dealer in rare gemstones and coloured diamonds, who opened new gateways to gemstone trade in Asia and helped build trading networks in the US and Europe, to develop its business in Australia, where he is a leading supplier of local opals and sapphires.

Mark, director for Australia of the International Colored Gemstone Association (ICA), specialises in mine to market Lightning Ridge black opals, along with a broad range of scarce coloured gemstones and fancy coloured diamonds.

Based in Albury in southern New South Wales, Australia, he owns and runs Tremac Pty Ltd, a longstanding trusted business supplying gemstones to clients around the world.Mark Tremonti

Mark Tremonti

As Gembridge’s Australia ambassador he will bring in respected Australian coloured gemstone suppliers to deepen the market, and will add certified rare, predominantly Australian coloured gemstones to the platform’s listings.

“I will bring to Gembridge a display of my passion and expertise in offering irresistible Australian opals, natural unheated sapphires, and other rare gemstones,” Mark said. “Quality always sells.”

“We are delighted to welcome Mark as our Australian Ambassador. He is a trailblazer and a highly respected member of the global coloured gemstone community,” said Tony Brooke, Gembridge Chairman.

“Gembridge shares Mark’s commitment to quality, and his experience will be invaluable as we build a global marketplace the world trusts,” added Nick Marrett, Gembridge CEO.

Mark has always been a “rock-hound”. In the early 1980s, as a young man looking for work, he travelled to the sapphire fields of Queensland, and on to the black opal deposits of Lightning Ridge.

He learnt to mine, identify, cut, treat and grade the rough sapphire that he obtained, and developed his passion for Australian opal.

Looking to build his business internationally, with the encouragement of Australia’s leading trade and investment agency, Austrade, he established an office in the diamond district of Hatton Garden, London, to export Australian gemstones.

The business, then known as Tremonti Mclauchlan Gemstone Traders, focused on selling calibrated gemstones along with high-end jewellery and collectables in the UK, Germany, France and Switzerland.

Mark refocused his trade to Asia and America, and was one of the first to supply black opals to the Japanese market.

He also assisted in establishing some of the first gemstone trade shows and missions to Taiwan and Japan.

In the early 1990s, while living and trading in Japan for most of each year, Mark opened an office in New York to develop his connections with the coloured diamond community and to educate American buyers on the beauty and value of coloured gemstones.

He became well known as an exhibitor at the many trade shows of that time, notably Baselworld. He was one of the founding exhibitors at the Tucson Gem & Mineral Show.

He became a member of the ICA in 1994 and was made Australian Director at the ICA Congress in Brazil in 1996.

Mark was voted as ICA Director for Australia for a second time in 2020.

After many years living overseas, the lure of home saw Mark move back to Australia in the mid-1990s to open his office in the Dymocks Building, Sydney, and settle down to have a family.

Today, Tremac Pty Ltd buys and processes rough opal, sapphire and rare coloured gemstones, supplying calibrated gemstones and collectables to the world market.

After a long career involving extensive travel, and now having a media profile as “Mark T the Opal Hunter”, Mark has many friends and associates in the gemstone community around the world.

Gembridge is helping to pioneer the digital transformation of the coloured gemstone trade. It provides a marketplace for members to buy, sell and consign, via a secure, verified and insured door-to-door service.

Gembridge is a commercial member of the World Jewellery Confederation, CIBJO, and is a member of the International Colored Gemstone Association (ICA) and the Responsible Jewellery Council (RJC.)

Gembridge is regulated by Singapore’s Ministry of Law for purposes of anti-money laundering and countering the financing of terrorism, in cooperation with the Financial Action Task Force.


Members of the trade are invited to register for Gembridge, free of charge, to join an exclusive membership with other respected industry players.

Once you complete the member verification process, you can view all prices, buy from our Showcase and list coloured gemstones on your own exclusive Shopfront.

We look forward to helping you TRADE WITH TRUSTTM.

Register, find out more or collaborate by completing this form:

The Gembridge online B2B platform is ‘live’ and currently in its test phase for functionality, user experience and systems.

For more information, please contact:

Tony Brooke

(M: +66 81 854 1755 E: [email protected])

Or Nick Marrett

(M: +65 9270 3875 E: [email protected])


Helen Molesworth

(+41 79 371 3700 E: [email protected])

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