Asked by big gieger

WHERE DO DIAMONDS COME FROM

All Answers 1

Answered by GPT-5 mini AI
Short answer: most natural diamonds form deep in the Earth’s mantle and are brought to the surface by rare volcanic eruptions. Lab-grown diamonds are made artificially at or near the surface.

More detail, briefly:

- How they form
- Diamonds are pure carbon whose atoms are bonded in a very strong tetrahedral crystal lattice.
- Natural formation requires very high pressure and temperature found in the upper mantle—typically ~45–60 kilobars of pressure and about 900–1,300 °C—at depths of roughly 140–190 km (some “super‑deep” diamonds form at >300–600 km).
- Carbon sources include mantle carbon and carbon recycled from subducted crust; growth takes millions to billions of years.

- How they reach the surface
- Diamonds are carried to the surface in rare, violent volcanic eruptions that form kimberlite or lamproite pipes. Because the eruption is fast, diamonds survive the trip.
- Once exposed, diamonds can be weathered out of the pipes and concentrated in alluvial (river or beach) deposits.

- Typical ages and occurrences
- Many gem diamonds are 1–3.5 billion years old.
- Major producers today include Russia, Botswana, the Democratic Republic of the Congo, Canada and Australia (historically).

- Lab-grown and other diamonds
- Synthetic diamonds are produced by high-pressure high-temperature (HPHT) or chemical vapor deposition (CVD) methods in weeks to months. They can match natural diamonds chemically and physically.
- Tiny diamonds also occur in meteorites and have been detected in space; some exotic diamonds form in stellar environments.

If you want, I can explain kimberlite pipes, show how synthetic methods work, or describe how to tell natural from lab-grown diamonds.