13 Rocks You Won't Believe Aren't Man-Made!

StellarSpindle Updated: 2025-07-05

2. Eye of the Sahara

For decades scientists, astronauts, and inquisitive spectators have been enthralled with the geological wonder known as the Richat Structure, often dubbed as the Eye of the Sahara. This enormous creation, found in the Sahara Desert close to Ouadane, Mauritania, is evidence of the Earth's capacity to produce breathtaking scenery by natural events. Known as "the Eye of the Sahara," the circular form and great scale of the structure—about 30 miles in diameter—make it obvious from distance.
At first, many specialists thought the precisely round form of the Eye of the Sahara resulted from a meteorite collision. Given the structure's similarity to recognized impact craters elsewhere on Earth, this idea looked reasonable. But as researchers dug more deeply, another narrative started to surface. Modern scientists now hold that the amazing formation we observe today was created totally by erosion, a process spanning millions of years.
Rising almost 650 feet above the nearby desert, the structure rests on an elevated platform. The development of the Eye has been much aided by this elevation differential. The Eye of the Sahara is, according to geologists, a quite severely degraded rock dome. A geologic dome is a kind of structural feature in which the oldest rocks are at the center and progressively younger rocks form rings moving outward from the center, bent into an anticlinal configuration.
About 600 million years ago, during the late Proterozoic to early Cambrian period, the Eye first developed. Significant geological activity in the area was resulting from the supercontinent Gondwana starting to split at this point. As magma rose from deep inside the Earth, the underlying sedimentary rocks bulged upward in a dome form.
Erosion has progressively removed the top layers of this dome over millions of years, revealing the circular rock foundation. The several rings seen in the Eye match the several kinds of rock that were first placed one on top of another. Ordovician sandstone makes up the outermost ring; advancing inward one finds strata of Proterozoic quartzites and other metamorphic rocks. A core of several igneous rocks—including rhyolitic volcanic rocks, gabbros, and carbonatites—lies at the very heart of the structure.
Differential erosion of these several rock types accentuates the special circular pattern of the Eye. Whereas weaker rocks erode more quickly and create valleys between the ridges, harder, more resistant rocks create ridges. Over millions of years, this process—shaped by wind, water, and temperature changes in the hostile desert environment—has continued.
Geologists and Earth scientists still find great appeal in the Eye of the Sahara. Its development offers important new perspectives on the geological processes sculpting our globe over very long times. Furthermore, for astronauts circling the Earth, the structure's obvious presence from space is significant. Many have said they passed across the great expanse of the Sahara Desert using the Eye as a compass.
The Eye of the Sahara draws brave visitors attracted by its exotic look and geological importance despite its far distance. But since the site is isolated and the surrounding desert conditions are severe, reaching there calls for meticulous planning and guided trips. The Eye of the Sahara is a wonderful evidence of the dynamic geological processes of the Earth and their capacity to produce amazing landscapes over millions of years as research on them keeps on.