Gem Diamonds Limited
Gem Diamonds Limited is a London-headquartered (LSE main market), London Stock Exchange-listed diamond producer. Its core asset is a 70% interest in the Letseng mine in Lesotho, the highest dollar-per-carat kimberlite diamond mine in the world, renowned for producing large, exceptional white (and occasional pink/blue) diamonds. The company also owns 100% of the Ghaghoo mine in Botswana, which it is in the process of selling. Sales, marketing and diamond sorting/manufacturing run through Antwerp, Belgium. Diamonds have no primary commodity tag, so the company is classed under Other, with its resource recorded in carats.
Lifecycle Milestones
Construction Milestones
5 of 5 reached- Reached — date not disclosed · Source
- Reached — date not disclosed · Source
- Reached — date not disclosed · Source
- Reached — date not disclosed · Source
- Reached — date not disclosed · Source
Milestones are recorded only from a company's own dated disclosure. A milestone with no date shown is one we can confirm was reached but for which no date was disclosed — we don't estimate one. "Not yet reached" means exactly that, not that a date is missing. An "Expected" line likewise only ever reflects the company's own guidance (e.g. a study or permit decision targeted for a stated quarter) — most not-yet-reached milestones have none, and that absence means no such guidance has been disclosed, not that one is overdue.
Not in place: grid power.
Jurisdiction (40%)7/10
Lesotho is a small, stable southern African constitutional monarchy with a long diamond-mining track record (Letseng operating since the 1970s), but with less-developed institutional/infrastructure depth than Botswana or the Tier-1 jurisdictions, consistent with a moderate risk score.
Infrastructure (40%)7.1/10
A confirmed mill, confirmed road access, no confirmed grid power, and a confirmed tailings facility at Letseng Diamond Mine.
Nearby producing mine (20%)Not yet researched
No producing mine within 50 km in our reference list (nearest listed: Harmony Free State operations (Welkom / Virginia) (Harmony Gold Mining Company Limited), 222 km). That list doesn't cover every mining district yet, so a longer distance isn't scored as remote.
Acquisition Susceptibility
A relative ranking of how closely this company matches the profile of juniors that have actually been acquired — not a probability, and not a reason to buy. Acquisitions are rare: only a few dozen significant deals happen a year across a universe of thousands of juniors, so even a high score here describes a long shot. The strongest signal in the research, a producer that already owns part of the company, is scored from its disclosed strategic shareholders. A producer that is a joint-venture or earn-in partner on the project, rather than a shareholder, isn't captured yet.
How this score is built
- Disclosed pending dealSub-score: Not scored
No pending acquisition or merger disclosed (checked)
Not scored: having no deal in flight isn't held against a company.
Weight 26.25% - Producer's strategic stakeSub-score: Not scored
No producer stake on file; largest strategic holder is Graff Investments Limited (14.9%) See holders
Not an operating producer, so it isn't the toehold-then-takeout pattern the research documents; a missing producer stake isn't held against a company.
Weight 25% - Distance to a producing mineSub-score:0/10
Nearest producing mine: Harmony Free State operations (Welkom / Virginia) (Harmony Gold Mining Company Limited), 222 km
10 next to a producing mine, 8 at 20 km, 5 at 50 km, 0 beyond 200 km.
Weight 22.5% · 46% here - Lifecycle stageSub-score:5.5/10
Stage: Production
Feasibility and permitting score 10, where deals cluster, and production 5.5; earlier stages score less, down to 1 at grassroots.
Weight 15% · 31% here - JurisdictionSub-score:7/10
Lesotho: jurisdiction score 7/10
Our jurisdiction score, used as is: higher means lower political and permitting risk.
Weight 6.75% · 14% here - CommoditySub-score:2/10
Primary commodity: Other
Gold 10, copper 8, silver 5, nickel and uranium 4, others 2: most majors' deals are for gold.
Weight 4.5% · 9% here
Weight is each input's share of the full score. “Here” is its share of this company's score: inputs that aren't scored are left out and the rest re-weighted, never counted as zero.
Your Rankings
Management Team
Founder (2005) and Chief Executive Officer of Gem Diamonds Limited. Studied commerce and accounting at the University of Cape Town before joining Anglo American in 1986, then E Oppenheimer & Son (rising to Managing Director) before leaving in 2005 to start Gem Diamonds, acquiring the Letseng mine in Lesotho in 2006 -- since the source of five of the twenty largest known white gem-quality diamonds on record. Gem Diamonds listed on the London Stock Exchange in 2007. Also Non-Executive Chairman of Zanaga Iron Ore Company Ltd. since 2009.
Group Chief Financial Officer of Gem Diamonds Limited since his promotion to the role and appointment to the Board on 22 April 2013 (joined the Group full-time as Group Financial Manager in March 2008, after an August 2006-February 2008 secondment to assist with the company's London IPO). Before Gem Diamonds, spent over 25 years at audit firm RSM Betty & Dickson in Johannesburg, South Africa, joining in January 1993 and becoming audit partner in March 2000.
Insiders, Investors & Smart Money
Notable shareholders and insiders whose involvement is worth knowing about, plus what we're seeing from institutional/large-investor activity.
Gem Diamonds is a real diamond producer (the Letseng and Ghaghoo mines). Graff Diamonds International, the major luxury diamond trading house, has been a long-standing 14.90% strategic shareholder (20,861,931 shares held through Graff Investments Limited, per Gem Diamonds' own major-shareholder table as at 28 August 2026) with an obvious industry interest in the company's output. The largest named financial holder is actually Hosking Partners LLP at 19.98%, a London-based global equity value manager with no particular mining focus; Lansdowne Partners, a similarly generalist UK hedge fund, separately holds about 13.3%. Institutional ownership overall is substantial at 39%.
No notable insiders tracked for this miner yet.
Reports, Presentations & Documents
We haven't parsed this company's PEA/PFS/FS recommendations yet — cut-off grade, mine life, DCF/NPV, and the report's own next-steps guidance are a planned research pass, not live data for every company yet.