Why Did Botswana Win the Diamond Lottery So Hard?

Summary

In August 2024, the Lucara Diamond Corporation revealed a remarkable 2,492-carat diamond found in Botswana's Karowe mine, the second largest ever discovered. Botswana's rich geological history, marked by the ancient Kaapvaal craton and numerous tectonic events, has made it a global diamond hotspot. Diamonds form deep in the mantle under intense heat and pressure, and Botswana has experienced multiple diamond-creating events. These processes, coupled with unique kimberlite eruptions, facilitate the ascent of diamonds to the surface, showcasing Botswana's unparalleled status in the diamond industry.

Takeaways

• 💎 A 2,492-carat diamond was discovered in Botswana's Karowe mine, making it the second largest diamond ever found.
• 🇧🇼 Botswana is home to the largest number of significant diamond discoveries, with seven of the ten largest diamonds originating from the country.
• 🌍 Diamonds form deep in the Earth's mantle, between 150 to 250 kilometers below the surface, under high pressure and temperature.
• 🪨 Diamonds require specific conditions to form, making their distribution uneven across the globe.
• 📏 Botswana's geological stability comes from its location on the Kaapvaal craton, a thick and ancient section of the Earth's lithosphere.
• 🌡️ The combination of pressure from the craton and lower temperatures in the mantle creates optimal conditions for diamond formation.
• ⚙️ The history of tectonic collisions in Botswana has contributed to more frequent diamond-creating events than anywhere else known.
• 🌊 Oceanic plate subduction brings additional carbon and water into the mantle, aiding the formation of diamonds.
• 🌋 Kimberlite eruptions, which transport diamonds to the surface, occur in sudden and violent events, primarily within cratons.
• 🔍 Recent research suggests that kimberlite eruptions may be influenced by vortices in the mantle created by the breaking apart of supercontinents.

Q & A

What was the significance of the 2,492-carat diamond discovered in Botswana in August 2024?

The discovery of the 2,492-carat diamond by Lucara Diamond Corporation highlights Botswana's status as a leading source of large diamonds, being the second largest diamond ever found.

Why are diamonds primarily found in Botswana?

Botswana is located on the Kaapvaal craton, which provides the right conditions of high pressure and relatively cool temperatures in the Earth's mantle necessary for diamond formation.

What are cratons, and why are they important for diamond formation?

Cratons are thick, stable parts of the Earth's lithosphere that help maintain the high pressure needed for diamond formation. Botswana's Kaapvaal craton is particularly old and stable, making it ideal for diamond production.

How do tectonic events contribute to the abundance of diamonds in Botswana?

Repeated continental collisions have thickened and strengthened the craton, while also delivering carbon from subducted oceanic plates, which is essential for diamond formation.

What role does the Earth's mantle play in diamond formation?

Diamonds form in the Earth's mantle at depths of 150 to 250 kilometers, where there are high temperatures and pressures that allow carbon atoms to arrange into a diamond structure.

What is kimberlite, and why is it significant in diamond mining?

Kimberlite is a type of igneous rock that often contains diamonds. It typically erupts from deep within the mantle to the surface, carrying diamonds with it, and is sought after by miners for this reason.

What is the connection between oceanic subduction and diamond formation?

Oceanic subduction drags carbon-rich oceanic crust into the mantle, which, combined with water, contributes to the chemical processes that create diamonds.

How many diamond-creating events have occurred in Botswana, and why is this significant?

Botswana has experienced at least seven diamond-creating events, more than any other known location, which has led to a significant accumulation of diamonds beneath the surface.

What recent research suggests about the timing of kimberlite eruptions?

Recent research indicates that kimberlite eruptions tend to peak around 30 million years after a supercontinent breaks apart, likely due to geological processes occurring at that time.

Why might Botswana's geological history lead to even larger diamonds in the future?

The combination of a stable craton, repeated tectonic activity, and the presence of abundant raw materials suggests that Botswana could continue to produce exceptionally large diamonds, potentially larger than the recently discovered 2,492-carat gem.