Harder Than Diamond? The New Hexagonal Diamond Breakthrough (EP 38)

Harder Than Diamond? The New Hexagonal Diamond Breakthrough (EP 38)

From From First Principles by Krishna Choudhary and Lester Nare

April 15, 2026 · 58 min · Season 2 · Episode 38

About this episode

This episode explores the synthesis and significance of hexagonal diamond, a material that could surpass conventional diamond in hardness.

Hosted by Lester Nare and Krishna Choudhary , this episode is a deep dive into one of the strangest and most hard-fought materials science stories in decades: the claim that researchers have finally synthesized bulk hexagonal diamond, also known as lonsdaleite. They break down why this material matters, how it differs from ordinary cubic diamond, why scientists argued about its existence for more than 50 years, and what the new Nature paper actually did to convince skeptical reviewers. Summary Why hexagonal diamond matters — if real, it is a long-sought carbon phase that could be slightly harder than conventional diamond and useful in extreme industrial settings. The first-principles chemistry — carbon allotropes, x-ray crystallography, cubic diamond, and the ABAB stacking that makes hexagonal diamond different. The experimental breakthrough — how the new team engineered around the default pathway to ordinary diamond by controlling graphite orientation and pressure direction. The controversy — why the peer review was intense, and how the new paper relates to an earlier 2025 Nature paper with a similar claim. Support the show Donate: FFPod.com/donate Follow: @FFPod on X /…

People in this episode

Hosts: Lester Nare, Krishna Choudhary

Topics covered

  • materials science
  • hexagonal diamond
  • lonsdaleite
  • carbon allotropes
  • peer review
  • experimental breakthrough

Keywords

  • hexagonal diamond
  • lonsdaleite
  • materials science
  • cubic diamond
  • carbon phase
  • peer review
  • experimental breakthrough

Mentioned in this episode

Books & works: Nature, Nature paper, 2025 Nature paper

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