Skip to main content

A collection of calcite crystals discovered in a rock shelter in South Africa's Kalahari Desert.Nature/Handout

A discovery in South Africa’s Kalahari Desert reveals that a fondness for crystals is more than a New Age fad. It may be as old as culture itself.

Researchers excavating the site of an ancient rock shelter at Ga-Mohana Hill in the Kalahari Basin unearthed stone tools, animal bones and other signs of human occupation. Among the findings were 22 crystals of calcite, a white-coloured mineral, ranging in size from about one-half to three centimetres across.

Study leader Jayne Wilkins, a Canadian archaeologist based a Griffith University in Queensland, Australia, said she and her colleague weren’t sure what to make of the crystals at first. They systematically ruled out any geological explanation for the deposit and concluded the crystals had been brought there by the people who inhabited the shelter about 105,000 years ago. The question is why.

“Walking around with a crystal in your pocket isn’t going to help you to get a meal or find water,” said Benjamin Collins, a University of Manitoba researcher who helped analyze the materials.

According to Dr. Wilkins, the fact the crystals show no signs of being worked or incorporated into tools suggests they served a different purpose, possibly in some sort of ritual practice.

“Items like these are generally associated with the deep roots of symbolism, art and culture,” she said, adding the crystals were likely chosen for the same reason that people are attracted to crystals today – because of their visual beauty.

What makes the find significant is it corresponds to a time when signs of cultural activity were just beginning to appear in the archeological record. For the most part, those signs have been confined to sites along the South African coast, where some experts have speculated a bountiful environment and possibly a seafood diet helped to spur the emergence of higher thought.

The Kalahari evidence suggests the phenomenon was more widespread and early humans living in the more challenging interior regions of Africa were just as complex.

“I think what it does is demystify the coastline as a source of innovation.” said Genevieve Dewar, an anthropologist at the University of Toronto who is not involved in the find. “It’s not always going to be the case that people innovate [only] when life is great.”

Dr. Dewar added a distinguishing feature of the discovery is the precision with which the researchers were able to establish the date of the crystals. One method used in the study, known as optically stimulated luminescence, requires carefully gathering soil samples in the dark and then measuring the energy trapped over time in individual specks of quartz making up the sandy soil.

A report of the findings by Dr. Wilkins and her team was published on Wednesday in the journal Nature.

Our Morning Update and Evening Update newsletters are written by Globe editors, giving you a concise summary of the day’s most important headlines. Sign up today.