Chimpanzee study reveals deep evolutionary roots of human fascination with crystals

A new chimp study finds that primates are naturally attracted to the transparency and symmetry of crystals, explaining why human ancestors collected them for 780,000 years.

By: AXL Media

Published: Mar 4, 2026, 9:39 AM EST

Source: The information in this article was sourced from Frontiers

A prehistoric obsession with the polyhedral

For nearly 780,000 years, the ancestors of modern humans have been collecting crystals. Archaeologists have consistently discovered these stones at Homo sites, despite no evidence that they were ever utilized as tools, weapons, or jewelry. This persistent, non-utilitarian fascination has long puzzled researchers. A new study published in Frontiers in Psychology by scientists in Spain suggests that this "infatuation" is not unique to the human branch of the evolutionary tree. By observing chimpanzees—one of our closest living relatives—researchers have identified that the natural geometry and clarity of crystals trigger a deep-seated curiosity that likely predates the divergence of the two species six to seven million years ago.

The "Monolith" experiment

Lead author Prof. Juan Manuel García-Ruiz and his team designed experiments with two groups of enculturated chimpanzees at the Rainfer Foundation. In the first trial, a large quartz crystal, dubbed "the monolith," was placed alongside a standard rock of similar size. While both objects initially drew interest, the chimps quickly disregarded the normal rock in favor of the crystal. The apes were observed rotating and tilting the crystal to view it from specific angles, demonstrating an active interest in its refractive properties. One chimp, Yvan, even claimed the object as a valuable, carrying it back to the dormitory area and only surrendering it to caretakers in exchange for high-value treats like bananas and yogurt.

Rapid identification and sorting

A second experiment tested the chimps' ability to identify smaller crystals within a pile of 20 rounded pebbles. Within seconds, the chimpanzees were able to select quartz, pyrite, and calcite crystals from the mundane stones. A chimp named Sandy displayed remarkable cognitive sorting, separating the three distinct crystal types based on their transparency and luster. Interestingly, the chimps often carried these crystals in their mouths—a behavior not typically seen with common objects—which researchers interpret as an attempt to hide or protect items perceived as valuable. This ability to recognize a "crystal-type" object across different chemical compositions suggests a sophisticated level of visual pattern recognition.