A recent study has revealed that Neolithic builders at the Motza site near Jerusalem mastered a highly complex plaster production technique nearly 8,000 years before the Romans. The discovery of pyrogenic dolomite in plaster floors dating back 10,000 years overturns long-held assumptions about ancient construction technologies and demonstrates that Pre-Pottery Neolithic communities used these materials long before written history began.
Before this discovery, the earliest documented use of dolomitic lime plaster had been traced to the Roman period. That gap of nearly 8,000 years makes the Motza find a significant leap backward in construction history, and one that challenges the assumption that sophisticated material science was a product of classical antiquity. The ancient craftspeople of Motza were not simply building floor, they were conducting a form of applied chemistry that even modern researchers have struggled to replicate in laboratory conditions.
The findings, published in the Journal of Archaeological Science, were led by Yonah Maor of the Israel Antiquities Authority and colleagues from the Weizmann Institute of Science.
The Motza Megaproject and Its Plaster Floors
Located approximately five kilometers west of Jerusalem in the Judean Hills, the Motza site was excavated between 2015 and 2021 ahead of highway construction in what became known as the Motza Megaproject. The massive Pre-Pottery Neolithic B settlement, dating from around 7100 to 6700 BC, covered more than three hectares and yielded over 100 plastered floors across multiple building complexes. While lime plaster was a known Neolithic achievement—seen at sites such as Ain Ghazal and Jericho—the Motza floors contained something entirely unexpected.
Researchers discovered that the builders were not just using standard limestone. They were actively processing dolomite, a calcium magnesium carbonate mineral that requires significantly more advanced technical control to transform into usable plaster. The earlier floors from the Middle Pre-Pottery Neolithic period were exceptionally well preserved, with some even retaining distinct red pigments, while later floors were thinner and more porous by comparison.
- 9000 Year-old 'Mega Site' Found Near Jerusalem Changes History
- Shaman Found in 9,000-Year-Old Tomb – and She Had Six Fingers on One Hand!
Structure of plaster in floors in area B10. (Assaf Peretz/ Journal of Archaeological Science)
Mastering the Dolomite-Lime Cycle
The process of making dolomitic plaster is notoriously difficult. When limestone is burned in a process called calcination, it creates quicklime, which is then slaked with water and mixed to produce plaster. Dolomite, however, contains both calcium and magnesium carbonate. If not fired at carefully controlled temperatures—specifically below 900 degrees Celsius—the resulting mix of magnesium compounds tends to be weak, unstable, and unsuitable for high-quality construction. This is precisely why geologists have spent decades grappling with what is known as the "dolomite problem": the mineral is abundant in ancient geological formations yet rarely forms under modern conditions.
At Motza, archaeologists found shallow fire pits, 1.5 to 2.6 meters in diameter, with fire-reddened edges that served as stone-firing kilns. Crucially, not all the pits contained the same type of stone. One pit was filled with calcite (limestone) stones, while an adjacent pit contained only dolomite. Both had been exposed to fire, but separately. Researchers believe this separation reflects a deliberate understanding that dolomite and limestone require different thermal treatments. The ancient builders successfully achieved what the study describes as a complete dolomite-lime cycle, where the dolomite fully re-formed after firing—a feat that Roman and medieval plasterers could not consistently replicate.
- Ancient Formula for Super-Durable Maya Plaster Finally Revealed
- Phoenicians Pioneered Hydraulic Plaster Technology Before Romans
A Lost Technology with Modern Implications
The use of dolomite offered significant practical advantages for the Neolithic builders of Motza. The site sits directly atop a dolomite-rich bedrock, meaning the material was locally available without the need to transport limestone from elsewhere. Dolomite also calcines at a lower temperature than limestone, potentially reducing fuel consumption. Most importantly, dolomitic plaster produces a significantly harder and more water-resistant surface than standard lime plaster—properties that made it highly desirable for floors and structural installations.
Close-up of red paint preserved on a plaster floor in sub-area A10 at Motza. (Assaf Peretz/ Journal of Archaeological Science)
This sophisticated approach mirrors advice given thousands of years later by the Roman architect Vitruvius, who in the 1st century BC wrote that dolomite was preferable for structural mortars and limestone for final plasters. The Motza builders appear to have followed exactly this logic: the base structural layer is rich in dolomite, while the surface finish layer is almost pure calcite. As the study's authors conclude, the Pre-Pottery Neolithic residents of Motza "adapted the standard lime- or gypsum-based recipes to intelligently use local materials."
The discovery also carries potential implications for modern sustainable construction. Using local dolomite instead of transported limestone reduces fuel use, and since dolomite calcines at a lower temperature, it requires less energy to produce plaster. In an era of growing concern about carbon emissions, these ancient efficiencies are far from trivial. The authors also note that if dolomite can truly reform under Neolithic plaster conditions, the finding may offer new clues to resolving the long-standing geological dolomite problem.
Extraordinary Skill Lost to History
The researchers do not conceal their admiration for the technical skill of these Neolithic artisans. Producing quality dolomitic plaster demands precision at every stage: firing temperatures must be carefully controlled, slaking must be done correctly, and the mixing and curing process must be managed with care. "Considering the discussions in modern literature about the difficulties of producing high-quality dolomitic plaster, for a PPNB community to have done this would be a remarkable feat," the authors write.
The complexity of the process likely explains why dolomitic lime appears so rarely in the archaeological record and why the technique was eventually lost to history altogether. It did not resurface until the Roman period, and even then, the full dolomite-lime cycle observed at Motza was not replicated. In the 19th and 20th centuries, dolomitic plaster fell out of favor entirely, criticized by scientific studies as inferior. Only in recent decades, after analysis of historic buildings that used it and endured for centuries, has it regained interest. Now, Motza shows that the true origin of this technology lies deep in the Near Eastern Neolithic, and that the builders of this ancient settlement achieved something that, as the authors put it, "was thought physically impossible."
Top image: Plaster floors in sub-area A10 at the Motza Neolithic site, near Jerusalem. Source: Assaf Peretz/ Journal of Archaeological Science
By Gary Manners
References
Buyukyildirim, O. 2026. 10,000-Year-Old Plaster Floors at Motza Reveal a Lost Neolithic Technology Once Thought to Be Roman. Available at: https://arkeonews.net/10000-year-old-plaster-floors-at-motza-reveal-a-lost-neolithic-technology-once-thought-to-be-roman/
Carvajal, G. 2026. Discovery Shows a Complicated Construction Technique Thought to Be Roman Was Used 8,000 Years Earlier at the Neolithic Site of Motza. Available at: https://www.labrujulaverde.com/en/2026/04/discovery-shows-a-complicated-construction-technique-thought-to-be-roman-was-used-8000-years-earlier-at-the-neolithic-site-of-motza/
Maor, Y., Yegorov, D., et al. 2026. Neolithic plaster floors at Motza: Earliest case of burning dolomite for plaster. Journal of Archaeological Science, Volume 190, June 2026, 106557. Available at: https://doi.org/10.1016/j.jas.2026.106557
Moeed, A. 2026. Ancient Builders Mastered Dolomitic Lime Plaster 8,000 Years Before the Romans. Available at: https://greekreporter.com/2026/04/30/ancient-builders-dolomitic-lime-plaster-before-romans/
