All over the world, we find rocks with highly distinctive and peculiar shapes, known as “discoid rocks” or “discoidal rock formations.” These geological curiosities intrigue scientists, mystery enthusiasts, and the general public alike.
These formations stand out due to their striking resemblance to classic “flying saucers,” making them even more fascinating. They feature circular, flattened, or slightly convex contours that evoke the image of unidentified flying objects. Such rocks can be found in various regions of the world, including the deserts of Utah and Arizona in the United States, the Caucasus Mountains in Russia, and remote areas of China. Generally, science attributes their formation to natural processes such as differential erosion, which occurs when wind, water, and other climatic agents wear away different layers of rock over time. Other processes, such as compaction and sedimentation over ancient geological periods, also help explain these formations.
However, these rocks are not limited to being merely geological phenomena. They also fuel speculations and alternative theories, often associated with ufology and the paranormal. Some theorists suggest that these formations could be remnants of ancient extraterrestrial visits, hypothesizing that they might be fossilized artifacts of spacecraft that landed on our planet thousands of years ago. Others believe they could be creations of advanced, long-lost civilizations that used unknown technologies to shape them. In places like Volgograd, Russia, where there are concentrations of discoid rocks, it is not uncommon to hear reports from locals about sightings of mysterious lights in the sky, which further reinforces the mystical appeal and their connection to the UFO phenomenon.
Beyond scientific explanations and speculative theories, many cultures attribute spiritual or supernatural meanings to these formations. For them, these rocks are seen as sacred objects or manifestations of forces beyond human understanding. This combination of science, folklore, and mystery makes flying saucer-shaped rocks an intriguing topic that transcends the boundaries between the natural world and the popular imagination.
Below we will see some examples:
1. The Huaco UFO Stone, Argentina

The Huaco UFO Stone was discovered by a group of young mountaineers in 2005 in the province of La Rioja, Argentina, located about 1,200 km from Buenos Aires. The sculpted stone, approximately 10 cm in diameter, features a series of concentric rings that have led many researchers and enthusiasts to associate it with representations of flying saucers.
In addition to the remarkable geometric features, the discovery of other indigenous artifacts in the vicinity, such as mortars and stone tools, suggests that the piece could have been created by an unknown local culture, possibly related to the Comechingones, an indigenous people who inhabited the region before the Spanish conquest.
Studies on the stone are still limited, and although some people defend the theory that the stone might represent a “flying saucer,” other scholars suggest that it could simply be an example of ritualistic craftsmanship, without any connection to the UFO phenomenon. The “flying saucer” theory draws on elements found in some indigenous cultures, which had stylized representations of circular objects and other celestial phenomena in their mythologies.
2. The UFO Stones of Jiangxi, China

In May 2007, a large number of mineral stones with circular, rounded shapes resembling flying saucers were found in Shangrao County, Jiangxi Province, China. The phenomenon attracted widespread attention from both the media and the scientific community due to the peculiar nature of the stones and their ancient age.
The stones in question range in thickness from 20 cm to 60 cm and weigh between 800 kg and 1 ton. According to geologists, these stones were formed about 300 million years ago, during the transition from the Carboniferous period to the Permian, at the end of the Paleozoic era. They were found within a pile of minerals, and one theory suggested that they were formed by natural processes, such as tectonic pressure and mineral deposition.
However, the fact that the stones were aligned symmetrically and displayed a regular pattern led some people to associate the discovery with extraterrestrial theories. Others, more skeptical, argue that the arrangement of the stones could simply be a natural phenomenon resulting from erosion or an ancient geological process. The mystery continues to be debated, especially after similar stones were discovered near the Shuibuya Dam in Sichuan.
The stones are not the only geological mystery in the area. Some rock formations in nearby regions, such as Nanchang, also exhibit unusual features, leading to more speculative theories about the nature of these rocks.
3. The Nazca UFO Stone, Peru

The Nazca UFO Stone, discovered in 1960, is one of the most intriguing archaeological finds related to unconventional artifacts. The stone was found in the Nazca Desert, an area famous for the Nazca Lines, which are monumental, mysterious geoglyphs. The stone displays several sculpted symbols, including a spiral, a spider, a human face, circles, and a crocodile, which bear a striking resemblance to the geoglyphs of the region.
Some theorists suggest that this stone was left behind by an ancient civilization as a form of map or message for extraterrestrial visitors. Another hypothesis is that it could have been a “manual” for other cultures, explaining how to navigate or interpret the geoglyphs of the Nazca Lines.
The mystery surrounding this stone has grown due to its estimated age of around 700 to 800 years, though some scholars question its true antiquity due to its weathered appearance. No detailed analysis of the stone has been conducted, as the owner of the piece was unable to find a laboratory or university willing to investigate it because of its UFO-like nature. Additionally, the stone exhibits an inexplicable weight for its size, which further fuels the mystery. The stone weighs approximately 3.2 kg and measures 17.7 cm in width and 11.5 cm in height.
4. The Foyel UFO Stone, Argentina

The Foyel UFO Stone was discovered in November 1993 by Hugo Rodríguez, a resident of San Carlos de Bariloche, Argentina, near the Foyel River in the Río Negro Province. The stone’s perfectly round and polished shape, along with its perfect point of balance, led researchers from around the world to debate its origin. Many have associated it with non-natural objects, while others have pointed out that it could be the result of geological processes.
The stone is about 8 cm in diameter and 3.5 cm in height, with a shape resembling what Kenneth Arnold described in 1947 when he reported seeing “flying discs” during his famous sighting near Mount Rainier in the United States. Arnold described the objects as having a shape similar to “soup plates,” which closely matches the shape of the Foyel Stone.
The mystery of the stone was fueled by the lack of clear scientific explanations regarding its origin. Some experts suggest that the stone could have formed through erosion, but others believe it could have been shaped by some form of ancient technology or, more speculatively, by extraterrestrial intelligence.
In 2015, Argentine researchers conducted a more thorough study but found no definitive answers. The stone remains an enigma in archaeology and ufology, with many believing it could be a relic of a lost civilization or even an alien message.
5. The Kuzbass UFO Stone, Russia

In February 2015, miners in the Kuzbass coal mine in Russia discovered a mysterious stone that resembled a flying saucer. The stone is round, with a diameter of 1.2 meters and weighing about 200 kg. Its composition seems to be claystone, and many researchers are wondering whether the stone is the result of natural processes or if it has an artificial origin.
The mystery surrounding this discovery attracted significant interest from ufologists, who suggest that the stone could be an artifact left behind by an ancient civilization or even extraterrestrials. However, the scientific community remains skeptical, with many specialists believing that the stone’s peculiar shape could be explained by geological processes, such as compaction and erosion, which may have shaped the rock to resemble a “flying saucer.”
Local researchers, however, do not rule out the possibility that the stone was shaped by some form of human intervention or even by aliens. Although more studies are needed to determine its exact origin, the discovery has brought new attention to the Kuzbass mines and other geological areas in Russia, which are still being explored in search of other mysteries.
Although research on rock formations resembling UFOs is limited in the field of geology, various theories attempt to explain this phenomenon, often associating these formations with natural erosion processes or specific geological phenomena. In studying these formations, some geologists and researchers have proposed plausible explanations, suggesting that they may be the result of natural processes, such as:
- Erosion and differential weathering: Many rocks with unusual shapes, such as discs or circles, can be explained by differential weathering processes, where harder materials are preserved while softer surrounding materials wear away, creating rounded or flattened shapes. This process can occur over thousands or even millions of years, resulting in rocks that, at first glance, may appear to be artificially shaped.
- Sedimentary formations and tectonic pressure: Some geologists also suggest that certain rock formations may resemble discs or circular shapes due to tectonic pressures that alter the structure of rock layers over time, creating rounded or concave shapes.
Geologist Michael Allaby, in his book The Concise Oxford Dictionary of Earth Sciences, discusses how the erosion of sedimentary rocks can create circular and disc-like shapes, shaped by the action of water and wind over long periods of time. Meanwhile, Charles Lyell, considered one of the founders of modern geology, in his work Principles of Geology, describes how erosion and sedimentation processes can create geological features that, in a modern context, could be interpreted as “anomalous” formations, such as rounded stones or geometric shapes.
Although natural explanations for rock formations in the shape of UFOs are plausible, the mystery of these rocks persists in many cultures and among UFO enthusiasts. Erosion and geological processes may account for many of these formations, but the issue continues to spark curiosity and fascination, both among researchers and the general public.