--- title: Scientists rediscover how to make ancient Roman... description: Scientists at the University of Sheffield have replicated the color-changing optical effect of the ancient Roman Lycurgus Cup, a 1,600-year-old glass artifact... canonical: https://daily.dev/posts/scientists-rediscover-how-to-make-ancient-roman-colour-changing-glass-5fuo9unwx twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Scientists rediscover how to make ancient Roman colour-changing glass | daily.dev og:description: Scientists at the University of Sheffield have replicated the color-changing optical effect of the ancient Roman Lycurgus Cup, a 1,600-year-old glass artifact... og:url: https://daily.dev/posts/scientists-rediscover-how-to-make-ancient-roman-colour-changing-glass-5fuo9unwx og:image: https://api.daily.dev/og/posts/5fUO9unWX.png og:image:alt: Scientists rediscover how to make ancient Roman colour-changing glass og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Scientists rediscover how to make ancient Roman colour-changing glass **[Hacker News](https://daily.dev/sources/hn)** · 4 min read · 0 upvotes · 0 comments ## Summary Scientists at the University of Sheffield have replicated the color-changing optical effect of the ancient Roman Lycurgus Cup, a 1,600-year-old glass artifact that appears jade green under normal lighting and ruby red when lit from behind. The team embedded gold and silver nanoparticles, each a thousand times smaller than a grain of sand, into molten glass cooled from over 1,000C. The nanoparticles block blue and green wavelengths when light passes through, letting reds and oranges through, while scattering light to produce green when reflected. Ian Freestone of University College London said the result is much closer to the original's shades than a 1960s replication attempt, and noted the color was highly sensitive to furnace position, saying the Romans may have hit the jackpot. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How does the ancient Roman Lycurgus Cup change color from green to red? The glass contains gold and silver nanoparticles, each a thousand times smaller than a grain of sand, embedded during cooling from molten glass above 1,000C. When light passes through the cup, these nanoparticles block blue and green wavelengths, letting only reds and oranges through, making it appear ruby red when lit from behind. When light reflects off the surface, the particles scatter it, producing the jade green color seen under normal lighting. _Anyone fascinated by nanoscale material science can find more deep dives like this one on daily.dev._ ### Have researchers successfully recreated the Lycurgus Cup's dichroic glass effect? Yes, scientists at the University of Sheffield recreated the effect using an ancient recipe derived from a fragment of the original fourth-century Roman glass. Ian Freestone of University College London said this version is more precise and closer to the actual green and red shades than a similar attempt made in the 1960s, calling the new project 'more ambitious and more precise.' _Readers tracking breakthroughs in replicating historical materials science can follow coverage like this on daily.dev._ ## Community take How the wider developer community reacted, aggregated from 2 discussions and 13 comments across hackernews (as of 2026-10-26). **TL;DR:** Commenters mostly find the find interesting but push back on the framing, noting the underlying nanoparticle mechanism has been understood for decades and the real novelty is replicating the exact effect, not discovering it. **Sentiment:** 20% positive · 60% mixed · 20% skeptical **The case for** - Some appreciated the historical/cultural context about Romans valuing color-shifting gems and glass highly. - One found it a reminder of a genuinely lost ancient engineering skill worth re-learning. **The pushback** - Several argued the gold/silver nanoparticle mechanism has been known for decades, so 'rediscover' overstates the novelty. - One noted the headline framing is misleading and should instead credit the Romans' original achievement rather than the modern scientists. - Another pointed out the harder unsolved mystery is how the cage-cup carving itself was made, not just the glass coloring. **By community** - hackernews (mixed): Discussion mixes mild skepticism about the headline's novelty claim with genuine interest in the historical and technical context. **Hottest debate:** Whether this represents a genuine rediscovery or just a well-known effect being restated with new framing. **Open questions** - How were the intricate cage-cup carvings of the Lycurgus Cup actually produced? **Highlights** > This has been known for a long long time too (decades+), its not a recent discovery. > — [ipsum2 on hackernews · 1 comments](https://news.ycombinator.com/item?id=50236525) > I wonder if the more accurate title might be: Scientists Discover How Ancient Romas Made Color-Changing Glass. Meaning that I've seen many examples of glass that appears different colors under different circumstances, but apparently none that worked the way this cup does. > — [gcanyon on hackernews](https://news.ycombinator.com/item?id=50235514) > Now if only we knew how the cage cups (of which the Licurgus Cup is actually an example) were made... > — [pseudohadamard on hackernews](https://news.ycombinator.com/item?id=50238581) > The Romans appreciated much more the jewels with variable colors than those with fixed colors. Those among opals and pearls that exhibited a very strong play of colors, due to diffraction, were valued far above the gems with fixed color, like emeralds and rubies. Thus it is likely that this kind of glass, with different colors in transmitted and reflected light, was very expensive, so it is not surprising that in TFA a letter of one of the Roman emperors is cited, where he mentions receiving such cups as a gift, because they certainly would have been considered a gift worthy of an emperor. > — [adrian\_b on hackernews](https://news.ycombinator.com/item?id=50236093) > For those who don't care to be held hostage by the journalist as he forces you through a long winded narrative: gold and silver nano particles are embedded into the glass > — [voidnullvalue on hackernews · 1 comments](https://news.ycombinator.com/item?id=50234202) **Source threads** - [hackernews](https://news.ycombinator.com/item?id=50233828) · 43 points · 12 comments - [hackernews](https://news.ycombinator.com/item?id=50229027) · 7 points · 1 comments ## Similar posts on daily.dev - [A new way to “paint with light” to create radiant, color-changing items](https://daily.dev/posts/a-new-way-to-paint-with-light-to-create-radiant-color-changing-items-mis3r5qdb) · MIT News · 0 upvotes · 0 comments - [A Sloshing-Mercury-Powered Neon Light](https://daily.dev/posts/a-sloshing-mercury-powered-neon-light-ajd4eyah2) · Hackaday · 0 upvotes · 0 comments - [Researchers devise a full-color night vision goggle](https://daily.dev/posts/researchers-devise-a-full-color-night-vision-goggle-mdyl98oep) · Ars Technica · 1 upvotes · 0 comments - [Any Color You Like: NIST Scientists Create ‘Any Wavelength’ Lasers in Tiny Circuits for Light](https://daily.dev/posts/any-color-you-like-nist-scientists-create-any-wavelength-lasers-in-tiny-circuits-for-light-pyiyaxusb) · Hacker News · 0 upvotes · 0 comments - [Quantum phenomenon enables a nanoscale mirror that can be switched on and off](https://daily.dev/posts/quantum-phenomenon-enables-a-nanoscale-mirror-that-can-be-switched-on-and-off-1o195vebl) · Phys.org · 0 upvotes · 0 comments --- Tags: [#science](https://daily.dev/tags/science), [#nanotechnology](https://daily.dev/tags/nanotechnology) [View this post on daily.dev](https://daily.dev/posts/scientists-rediscover-how-to-make-ancient-roman-colour-changing-glass-5fuo9unwx) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Scientists rediscover how to make ancient Roman colour-changing glass","url":"https://daily.dev/posts/scientists-rediscover-how-to-make-ancient-roman-colour-changing-glass-5fuo9unwx","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/scientists-rediscover-how-to-make-ancient-roman-colour-changing-glass-5fuo9unwx"},"datePublished":"2026-10-25T21:11:10.053Z","dateModified":"2026-10-26T04:11:51.787Z","description":"Scientists at the University of Sheffield have replicated the color-changing optical effect of the ancient Roman Lycurgus Cup, a 1,600-year-old glass artifact...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/af6e07f45b6ed18f973c79df78b239e6?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/af6e07f45b6ed18f973c79df78b239e6?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Hacker News","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Hacker News","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/hn","url":"https://daily.dev/sources/hn"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/scientists-rediscover-how-to-make-ancient-roman-colour-changing-glass-5fuo9unwx","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"science,nanotechnology","timeRequired":"PT4M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Hacker News","item":"https://daily.dev/sources/hn"},{"@type":"ListItem","position":3,"name":"Scientists rediscover how to make ancient Roman colour-changing glass"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/scientists-rediscover-how-to-make-ancient-roman-colour-changing-glass-5fuo9unwx#faq","mainEntity":[{"@type":"Question","name":"How does the ancient Roman Lycurgus Cup change color from green to red?","acceptedAnswer":{"@type":"Answer","text":"The glass contains gold and silver nanoparticles, each a thousand times smaller than a grain of sand, embedded during cooling from molten glass above 1,000C. When light passes through the cup, these nanoparticles block blue and green wavelengths, letting only reds and oranges through, making it appear ruby red when lit from behind. When light reflects off the surface, the particles scatter it, producing the jade green color seen under normal lighting. Anyone fascinated by nanoscale material science can find more deep dives like this one on daily.dev."}},{"@type":"Question","name":"Have researchers successfully recreated the Lycurgus Cup's dichroic glass effect?","acceptedAnswer":{"@type":"Answer","text":"Yes, scientists at the University of Sheffield recreated the effect using an ancient recipe derived from a fragment of the original fourth-century Roman glass. Ian Freestone of University College London said this version is more precise and closer to the actual green and red shades than a similar attempt made in the 1960s, calling the new project 'more ambitious and more precise.' Readers tracking breakthroughs in replicating historical materials science can follow coverage like this on daily.dev."}}]} ```