Highlights

• The closure of Argyle Diamond Mine in 2020 marked a major structural shift, tightening global supply and ending Australia’s dominance in coloured diamonds.
• Global diamond production has declined from over 175 million carats to ~121 million, with limited new projects replacing ageing mines.
• The diamond market is highly fragmented and opaque, with pricing varying significantly based on the “four Cs” rather than a standard benchmark.
• Lab-grown diamonds have rapidly gained share, now accounting for ~47–53% of engagement ring sales due to prices up to 75% lower than natural stones.
• Natural diamond prices fell ~26% from 2022 peaks but show early signs of stabilisation heading into 2026.
• India, particularly Surat, remains the backbone of global diamond processing, handling over 75% of cutting and polishing activity.
• Supply constraints from mine closures (including Diavik Diamond Mine) could support long-term prices, but lab-grown competition continues to pressure demand and sentiment.

Chapter 1: Introduction to Diamond Investing on the ASX

Diamonds have long captivated the imagination of humanity. From their geological formation deep within the Earth's mantle to their emergence as symbols of love, wealth and status, diamonds occupy a unique position at the intersection of natural wonder and commercial enterprise. For investors on the Australian Securities Exchange (ASX), diamonds represent a niche but fascinating corner of the resources sector, offering exposure to a commodity that behaves quite differently from gold, iron ore or lithium.

Australia itself has a storied relationship with diamonds. The discovery of the Argyle diamond pipe in Western Australia's remote Kimberley region in 1979 transformed the global diamond industry overnight. At its peak, Argyle produced more carats than any other mine on Earth, accounting for roughly one-third of global output. More importantly, Argyle was the world's only significant source of rare pink and red diamonds, stones that have become the most sought-after gems on the planet. The closure of Argyle in November 2020, after 37 years of continuous operation, marked the end of an era for Australian diamond mining and sent shockwaves through the global coloured diamond market.

Yet the story of diamonds on the ASX is far from over. Several companies continue to explore for, develop and produce diamonds through operations both within Australia and internationally. From the frozen tundra of Canada's Northwest Territories to the alluvial deposits of Angola and the kimberlite pipes of Sierra Leone, ASX-listed diamond companies offer retail investors a diverse range of opportunities and risk profiles.

This guide is designed to give retail investors a thorough understanding of the diamond stocks available on the ASX as of early 2026. We will examine each company in depth, exploring their assets, financials, management teams and growth prospects. We will also set these companies within the broader context of the global diamond market, examining the forces that shape diamond prices and demand, including the increasingly significant challenge posed by laboratory-grown diamonds.

Before we dive into individual companies, it is worth noting some important characteristics that distinguish diamond investing from other commodity investments. Unlike gold, diamonds do not have a standardised benchmark price. Each stone is unique, graded according to the four Cs (carat, cut, colour and clarity), and priced accordingly. This makes diamond valuation inherently more complex and less transparent than precious metals investing. Diamond miners report revenue per carat figures that can vary dramatically from quarter to quarter depending on the size and quality of stones recovered.

Furthermore, the diamond industry operates through a relatively opaque value chain. Rough diamonds move from miners to a network of dealers, cutters and polishers (predominantly based in India, Belgium and Israel) before reaching retail consumers through jewellers and luxury brands. Each stage of this chain adds value and complexity, and the margins available to miners depend heavily on the efficiency of this downstream process.

For ASX-listed diamond stocks specifically, investors should also consider the additional layer of currency risk. Most diamond sales are denominated in US dollars, while these companies report in Australian dollars. Movements in the AUD/USD exchange rate can meaningfully impact reported revenues and profitability, sometimes amplifying or dampening the effects of underlying diamond price movements.

With these considerations in mind, let us begin our exploration of the diamond opportunity on the ASX.

Chapter 2: The Global Diamond Market in 2026

2.1 Market Size and Structure

The global diamond market encompasses both natural and laboratory-grown diamonds across jewelry, industrial and investment applications. As of 2025, the total market was valued at approximately USD 101 billion, with projections suggesting growth to around USD 130 billion by 2033. However, these aggregate figures mask significant divergence between the natural and lab-grown segments, which are increasingly following different trajectories.

The diamond jewelry segment remains the dominant end-use, accounting for the vast majority of consumer-facing demand. Global diamond jewelry retail sales were estimated at approximately USD 90 billion in 2023, with the United States representing the single largest market at roughly 51 per cent of global revenue. Other significant markets include India, China, Japan and the Gulf states, each with distinct consumer preferences and purchasing patterns.

On the supply side, global rough diamond production has been trending downward for over a decade. From peak levels exceeding 175 million carats in 2005-2006, annual production has declined to approximately 121 million carats by 2023 and is expected to remain below 130 million carats going forward. This contraction reflects the exhaustion of major deposits, the closure of significant mines like Argyle, and limited new mine development.

2.2 Major Global Producers

The global diamond mining industry is dominated by a handful of major producers. ALROSA, the Russian state-controlled miner, holds approximately 31 per cent of global production by volume, producing around 34.6 million carats of rough diamonds annually. De Beers, owned by Anglo American, commands approximately 29 per cent market share and remains the most influential name in diamond marketing and distribution. Together, these two companies account for roughly 60 per cent of global rough diamond output.

Other significant producers include Petra Diamonds (focused on South African operations), Lucara Diamond (known for exceptionally large stones from its Karowe mine in Botswana), and Gem Diamonds (operating the high-value Letseng mine in Lesotho). Rio Tinto, which was once a major diamond player through its Argyle and Diavik operations, is effectively exiting the diamond business with the closure of its last diamond mine, Diavik in Canada, in early 2026.

For ASX investors, it is important to understand where the companies listed on their exchange sit within this global hierarchy. The pure-play ASX diamond stocks are small by global standards, with combined market capitalization well under AUD 200 million. This places them firmly in the junior to mid-tier category, which carries both higher risk and potentially higher reward compared to the global majors.

2.3 Natural Diamond Pricing Trends

Natural diamond prices have experienced significant volatility in recent years. After reaching cyclical peaks in mid-2022, prices declined substantially through 2023 and 2024. By January 2025, natural diamonds were approximately 26 per cent cheaper than two years earlier. The average price of a one-carat natural diamond fell from around USD 6,819 in May 2022 to approximately USD 4,997 by December 2024.

However, these averages conceal important quality-based divergences. Premium diamonds, particularly those with top colour and clarity grades (D/IF and D/FL), have shown considerably more resilience, supported by demand from high-net-worth collectors and investors. Meanwhile, lower-quality stones, such as those graded J/SI1, have experienced steeper declines, falling from USD 2,641 to USD 2,357 in just the first two months of 2025.

Larger diamonds also demonstrate a pronounced size premium. While a one-carat stone of good quality might sell for USD 4,000 to 6,000, the per-carat price escalates dramatically for larger stones. A two-carat diamond of comparable quality commands USD 22,000 to 28,000 (a four to five times per-carat premium), while a three-carat stone can fetch USD 60,000 to 75,000. This non-linear pricing is particularly relevant for miners like Lucapa Diamond, which specialise in recovering large, exceptional stones.

By early 2026, there are tentative signs of price stabilisation in the natural diamond market. The combination of constrained supply (due to mine closures and reduced production) and resilient demand from the United States and India is beginning to bring the market closer to equilibrium. Industry analysts suggest that a more balanced supply-demand dynamic could emerge by mid-2026, though the shadow of laboratory-grown competition continues to weigh on sentiment.

2.4 Supply Pipeline Challenges

The global diamond supply pipeline faces significant headwinds in the medium term. Several major mines have closed or are approaching closure, and very few new large-scale projects are under development to replace them. Argyle's closure in 2020 removed approximately 10 to 14 million carats of annual production. Rio Tinto's Diavik mine in Canada completed its final production run in early 2026, removing another significant source of supply. The Renard mine in Quebec ceased operations in 2023 and is being repurposed as a lithium processing facility.

Even among operating mines, production challenges persist. Canada's Gahcho Kue mine has been running at a loss and faces pressure to scale back operations. Burgundy Diamond Mines' Ekati mine, while receiving government support, has suspended open-pit operations at Point Lake and reduced its workforce. These pressures reflect both market conditions and the geological reality that many existing mines are entering their later years.

This supply contraction is, paradoxically, a potential positive for diamond miners who can maintain profitable operations. With fewer carats entering the market each year, the fundamental supply-demand balance should tighten, theoretically supporting prices. However, this optimistic view must be tempered by the recognition that laboratory-grown diamonds are adding an entirely new and rapidly growing source of supply to the broader diamond market.

2.5 India's Central Role

No discussion of the global diamond industry is complete without acknowledging India's pivotal role in the value chain. India processes over three-quarters of the world's cut and polished diamonds, with the city of Surat in Gujarat serving as the global hub. The Surat diamond district hosts more than 3,500 processing units and employs approximately 800,000 workers, making it one of the world's largest concentrations of specialised manufacturing.

India's diamond cutting and polishing market was valued at approximately USD 23 billion in 2024 and is projected to reach USD 30 billion by 2032. The sector contributes around 7.5 per cent to India's GDP and 14 per cent of total merchandise exports, underscoring its economic significance. For ASX-listed diamond miners, the health of India's diamond processing sector is a crucial barometer of overall market conditions. When Indian factories slow production or stockpile inventory, it typically signals weaker demand throughout the pipeline.

In recent years, India's diamond sector has also embraced laboratory-grown diamond production, becoming a major manufacturer of CVD (chemical vapour deposition) diamonds alongside its traditional cutting and polishing activities. This dual role means that India's diamond industry will remain central to the market regardless of how the balance between natural and synthetic stones evolves.

Chapter 3: The Lab-Grown Diamond Revolution

3.1 Understanding the Disruption

If there is one factor that has fundamentally reshaped the diamond investment landscape in recent years, it is the explosive growth of laboratory-grown diamonds. What was once a marginal technology producing small, industrial-grade crystals has evolved into a sophisticated industry capable of creating gem-quality stones virtually indistinguishable from their natural counterparts. For investors in ASX-listed diamond stocks, understanding this disruption is essential.

Laboratory-grown diamonds are real diamonds in every chemical and physical sense. They are composed of pure carbon arranged in the diamond crystal structure and possess the same hardness, brilliance and optical properties as mined diamonds. The only difference is their origin: rather than forming over billions of years deep within the Earth's mantle, they are created in a matter of weeks using advanced technology.

Two primary methods are used to produce laboratory-grown diamonds. High Pressure, High Temperature (HPHT) replicates the natural conditions under which diamonds form, subjecting carbon to extreme pressures and temperatures. Chemical Vapour Deposition (CVD) grows diamond crystals layer by layer from a carbon-rich gas in a vacuum chamber. CVD has become the dominant technology, capturing approximately 45 per cent of market share by 2024, due to its ability to produce larger, higher-quality stones more efficiently.

3.2 Market Penetration and Growth

The speed at which laboratory-grown diamonds have captured market share has stunned many industry observers. In the engagement ring category alone, lab-grown stones now account for approximately 47 to 53 per cent of all sales, up from just 11 per cent in early 2020. Among Generation Z buyers, the figure is even more striking: roughly two-thirds of Gen Z engagement ring purchasers choose lab-grown diamonds.

The broader lab-grown diamond market reached approximately USD 26 billion in 2024, up from USD 19 billion in 2023, representing growth of around 36 per cent in a single year. Projections suggest the market will reach USD 55 billion by 2032 and potentially exceed USD 90 billion by 2034, growing at a compound annual rate of approximately 13 per cent.

This growth has been driven primarily by price. Lab-grown diamonds are now available at approximately one-quarter the price of comparable natural stones, a discount that has widened significantly as production costs have fallen. A one-carat lab-grown diamond with good colour and clarity specifications can now be purchased for under USD 1,000 at wholesale, compared to USD 4,000 to 6,000 for a comparable natural stone. At the retail level, the discount is typically 60 to 75 per cent, though some categories have seen discounts approach 80 to 90 per cent.

3.3 The Price Deflation Challenge

Perhaps the most concerning trend for the lab-grown segment itself is the rapid price deflation that accompanies increased production capacity. Lab-grown diamond wholesale prices declined by an additional 15 to 20 per cent through late 2025, continuing a trend that has seen prices fall approximately 74 per cent since 2020. This deflation raises serious questions about the long-term economics of lab-grown diamond production and, more importantly for our purposes, about how this pricing pressure cascades through to natural diamond markets.

For natural diamond miners, the lab-grown challenge operates on two levels. First, it directly competes for consumer spending in categories like engagement rings, where the emotional and symbolic value of the stone may matter more than its geological origin. Second, it creates a psychological anchor that makes consumers more price-sensitive when considering natural diamonds, even in segments where lab-grown stones are less directly competitive.

However, it is important to note that the impact is not uniform across all categories. Large, high-quality natural diamonds, particularly those above two carats, face relatively less competition from lab-grown alternatives because producing large, flawless lab-grown stones remains technically challenging and expensive. Similarly, naturally coloured diamonds, especially pinks and reds from sources like the now-closed Argyle mine, occupy a luxury niche that lab-grown stones have not meaningfully penetrated.

3.4 Industry Response

The natural diamond industry has responded to the lab-grown challenge through a combination of marketing, differentiation and supply management. The Luanda Accord, signed in June 2025 by diamond-producing countries and key industry organisations, committed to increased funding for the Natural Diamond Council's marketing initiatives. This accord represents a coordinated effort to reinforce the perceived value of natural diamonds, emphasising their rarity, geological heritage and emotional significance.

De Beers, the industry's most powerful marketing force, has shifted its strategy to clearly separate natural and lab-grown diamonds in consumers' minds, positioning natural diamonds as rare luxury goods and lab-grown stones as accessible fashion items. This bifurcation strategy aims to preserve premium pricing for natural stones while effectively ceding the lower end of the market to synthetic alternatives.

For ASX-listed diamond miners, the practical implications are significant. Companies that produce large, high-quality stones or rare coloured diamonds are likely better positioned to withstand lab-grown competition than those producing smaller, commercial-grade output. This distinction will become increasingly important as we examine individual company profiles in subsequent chapters.

Digital traceability is also emerging as a differentiator. Blockchain-based provenance tracking and advanced certification technologies allow natural diamonds to be traced from mine to market, providing consumers with assurance about the ethical and environmental credentials of their purchase. This transparency advantage may help natural diamonds maintain their premium positioning, particularly among socially conscious consumers.