The strangest rocks ever found
All around us, from the Earth’s force upon itself, we find structures that tell stories spanning millions of years. From tiny fragments of sediment coating seaside cliffs to monumental structures that appear almost alien or man-made, the forces of nature are at constant work, carving, cutting, and sculpting.
These natural formations have served as objects of value and the center of folklore to ancient people. However, some are the result of more recent events, and others might tell us stories of places far more distant than one might imagine.
The Richat Structure
If you could gaze into the eyes of the earth, they would look a lot like the Richat Structure. The rock formation, also known as the eye of the Sahara, is an elliptical dome in Mauritania. The deep erosion of the sedimentary rock has led to concentric rings that give the appearance of an iris and pupil emerging from the desert sands. These formations are high relief circular cuestas formed by quartzite, and the center of the formation is siliceous breccia.
Twenty miles north of Gerlach in Nevada is the Fly Geyser, a small geothermal vent, shaped like a series of melting Hershey’s Kisses. Thermophilic algae coat the geological formation, giving it characteristic bands of bright red and green hues. The geyser was originally formed as a result of drilling in the early 20th century, but the geyser contains unusually high amounts of silica. The silica concentration, in combination with the temperature, caused quartz formations within that would usually take upwards of 10,000 years to form, here showing themselves in under a century.
Geology and rock collection may seem like safe hobbies to embrace from the comfort of one’s own home, but there are a surprising number of rocks that can kill you. Orpiment is a bright yellow rock that smells strongly of garlic. It derives its scent from the high concentrations of arsenic in its deposits. The Chinese used it extensively in ancient warfare. It was crushed into dust and then coated upon arrows to make deadly projectiles for battle.
Fingal’s Cave looks like anything but a natural formation, but it is. The Scottish sea cave is formed entirely by jointed basalt columns from within a Paleocene lava flow. Both the interior and exterior exhibit patterns of stark geometric columns that look like carefully crafted architecture. It was known by the Celts as “The Cave of Melody” for the eerie acoustics of nearby crashing waves that reverberate throughout its hull to give the sense almost of standing inside a cathedral. The ancient Celts told stories of a giant that built a bridge across the sea. The Cave of Melody was the mouth at which it entered the land of Scotland.
Hypatia is a stone like no other. It was originally in Africa and thought to be a form of Libyan desert glass, but subsequent tests proved it to be far more interesting. Investigation proved that the stone was of extraterrestrial origin. Rocky (chondritic) meteorites still show a chemical composition similar to Earth, and this stone had nothing of the sort, or of any previously observed rock. It showed uncharacteristically large amounts of carbon and a tiny fraction of silicone, as well as large concentrations of interstellar dust and micro-scale carbon diamonds. Finally, it contained pure aluminum, alongside grains of nickel and phosphorous. All of these characteristic point to one of several possibilities: Hypatia may be the first observed comet core, a relic preceding our solar system, or a projectile from a solar system other than our own.