First Diamonds from Sierra Leone’s Tongo Mine Coming to Market
Australian company Newfield Resources is developing the mine and will sell its production through Bonas Group in Antwerp.

Newfield Resources Ltd., the company developing the mine, announced in late April it had inked an exclusive diamond sales and marketing agreement with Bonas for the mine’s production.
Via its partnership with Bonas, Tongo goods will be tracked from mine to market using Sarine Technologies’ traceability program, Newfield said.
The mine, which has been in the works for more than decade, is “well known for its high-quality material,” Bonas said.
Tender viewings of the Tongo material will take place on the first floor of the Bonas Group offices in Antwerp between May 16 and 20.
The sale is scheduled to close May 20 at 1 p.m. CET/7 a.m. EDT and will be an online, highest bid tender on Newfieldbids.com.
Bookings for the tender are invitation-only, but requests can be submitted to Bonas Antwerp. Interested clients are requested to call the office at +32 (0) 3233 7080.
Based in Australia, Newfield has been developing the Tongo Diamond Project since 2018, when it acquired the site from Stellar Diamonds.
The project comprises two adjacent mining licenses covering a combined area of 134 square kilometers (about 52 square miles) in eastern Sierra Leone with five primary kimberlite pipes.
The first two pipes Newfield will mine have been dubbed Kundu and Lando.
Newfield said processing from the underground and surface at Kundu continues to yield “encouraging results,” with a high proportion of what’s recovered turning out to be gem-quality diamonds.
It is believed Tongo will produce 8.3 million carats of diamonds over the span of its life, including an indicated and inferred resource of 3.03 million carats at Lando and 2.76 million carats at Kundu.
Newfield employed 200 people at the mine as of March 31, including graduate trainees, contractors, and interns. Of the 200, 166 (83 percent) are local Sierra Leonians and 128 (64 percent) have permanent employment contracts, it said.
Twelve percent (about 20 people) of the local employees are women. Newfield said it intends to increase the number of women working at the mine, in line with its diversity policy.
In addition to Tongo in Sierra Leone, Newfield is conducting diamond exploration in neighboring Liberia via two licenses covering 670 square kilometers (about 259 square miles), known collectively as the Kumgbo Kimberlite Project.
The Latest

The new showcase dedicated to Italian jewelry design is set for Oct. 29-30.

Take a gaze at the sky with this pair of platinum diamond-set star earrings with blue lace agate drops.

In 2026, the jewelry retailer will celebrate a milestone only a small percentage of family-owned businesses survive to see.

You deserve to know what you are selling–to protect your customers as well as your business and your reputation.

Jeffrey Zimmer's decades of leadership at Reeds Jewelers are defined by integrity, a love of sourcing gemstones, and a heart for community.


The new high jewelry design and production process takes 30 days or less from concept to completion, the auction house said.

The holiday catalog for 2025 features never-before-seen images of more than 100 one-of-a-kind masterpieces.

The upcoming show provides savvy retailers with the opportunity to stock their cases with best sellers in advance of the holiday season.

The brand has released a second installment of its collection of traditional and non-traditional commitment heirlooms.

Corey rescued New England chain Day’s Jewelers, preserving its legacy with strong people skills, pragmatism, and a “get-it-done” attitude.

Charles Robinson Shay was sentenced to life in prison plus 120 years while his accomplice, Michael James McCormack, got 75 years.

The Museum of Arts and Design's new exhibition features 75 pieces by the designer, best known for her work in the “Black Panther” films.

Timepieces at Luxury will take place at The Venetian and, like Luxury, will be invitation-only for the first two days.

The auction house named a new global head of jewelry, as well as a new head of the jewelry department for the Americas.

As chairman of Schwanke-Kasten Jewelers, Tom Dixon has been tasked with honoring the past and shaping the future of the family-run store.

Katty Villapando Lyte and Mica Rencher received a $10,000 grant for their business, Shimmer Culture LLC.

The parents of the Dallas Mavericks rookie bought their engagement ring at a Day’s store in Bangor, Maine, in 1997.

The trio of Advent calendars include a version with 18-karat gold and lab-grown diamond jewelry in a red lacquer jewelry box.

Created in collaboration with Nymphenburg Porcelain, the lock is part of a four-piece collection that took two years to bring to fruition.

Jewelry industry veteran Alisa Bunger has taken on the role.

“The Winter Egg” set the world auction record for a Fabergé piece twice at previous Christie’s sales.

The company will pay 1.5x silver’s current spot price for each pound of silver oxide batteries submitted.

The line includes a “Shadow” series crafted exclusively for the new men’s offering and reimagined styles from the brand’s core collections.

The rough on offer was recovered from a newer area at the Montepuez mine.

The retailer’s new collection of engagement rings and fashion jewelry is set with natural diamonds that are traceable via blockchain.

The champagne colorway in her newest “Ombré” collection combines white and trendy brown diamonds, a departure from her usual vibrant hues.

Kosann partnered with the Museum of Fine Arts, Boston, to create a set of necklaces inspired by the artwork on samurai sword handguards.