Why did Clovis toolmakers choose difficult quartz crystal? New study offers clues

Green Clovis quartz crystal point. Credit: Briggs Buchanan Quartz crystals are difficult to knap due to size, hardness, and crystalline structure, making them a "low-quality" raw material. However, the Clovis people of North America sometimes made points and other tools from this material despite its drawbacks. To determine whether the quartz crystal points of the Clovis were functionally comparable to those made from higher-quality toolstones, Dr. Briggs Buchanan and his colleagues conducted scaling and geometric morphometric analyses on Clovis crystal points. The study is published in Lithic Technology.The properties of quartzThe Clovis are the best-documented late Pleistocene hunter-gatherer group of northern America. They are known for creating stone tools from high-quality raw materials, including chert, obsidian, and rhyolite, due to their tendency to be homogeneous, fracture predictably, and be free of impurities.By comparison, low-quality, coarse-grained, heterogeneous materials such as siltstones, quartzites, and silicified stones are generally less used due to their difficulty to knap.However, quartz crystals have different properties from most quartzites, being generally fine-grained and often fracturing conchoidally, yet they are still difficult to knap due to their internal crystalline structure. Additionally, quartz crystal source locations are limited, further constraining the practicality of using this raw material for stone tool production.Determining whether these properties made Clovis points significantly different in either their size or shape from other Clovis points, may suggest that the use of quartz crystals as a raw material limited the functional capabilities of these points.Analyzing the quartz crystal pointsThe study analyzed 58 quartz crystal Clovis points gathered from published research papers and the Paleoindian Database of the Americas; of these, 33 were suitable for geometric morphometric analysis, while 56 had linear measurements suitable for scaling analysis.Despite being somewhat smaller on average than Clovis points made from other raw materials, quartz crystal points were overall relatively similar to the compared Clovis point toolkit."We found it surprising that, despite the difficulty in knapping quartz crystal, that the proportions of the points made from crystals were similar to points made on other raw materials," explained Dr. Buchanan. Three Clovis quartz crystal points.

Credit: Briggs Buchanan The results indicated that the quartz crystal points were likely functionally similar to other points, and yet, seemingly, the Clovis deliberately chose to knap this challenging material in lieu of higher-quality, more abundant alternatives.The researchers proposed two hypotheses. The first being that crystal quartz points were potentially harder than alternative raw materials. On a Mohs scale, quartz crystal ranks about 7, compared to obsidian at 5.5. However, chert, which was commonly used by the Clovis, ranges in hardness between 6.5 and 7, making this hypothesis unlikely.The second hypothesis hinged on the translucency, triboluminescence (sparking when struck), crystalline shape, and rarity of the material, which may have had symbolic or ritual significance."There are a number of historical and ethnographic studies that indicate quartz crystals in different regions were considered to be imbued with special properties," explained Dr. Buchanan. "In these societies, quartz crystals have been used for curing, spreading illnesses, or were considered to be powerful living objects."For example, among Californian Yuman peoples, quartz crystals (wii'ipay) are one of the most powerful objects in the supernatural universe. Usually left to shamans to use or try to control for both good and bad purposes, including divining the future, reading minds, and providing luck in gambling; however, a crystal can also kill the shaman that possesses it."It is possible that the Clovis regarded the quartz crystals as having similar supernatural properties. However, this did not prevent them from having a functional use, Dr. Buchanan emphasized, "In many traditional societies there is not a distinct difference between ritual or supernatural and functional objects, so the widespread evidence suggesting that quartz crystal was considered to hold supernatural status does not preclude its functional use."This is supported by the fact that these quartz crystal points came from various sites, including a cache, campsites, and quarrying locations.Future avenues of researchDr. Buchanan and his colleagues hope to expand the scaling methodology to other Clovis points to determine whether similarly low-quality materials, "including materials considered low-quality (like quartz crystals and other quartzites) and high-quality (for example, cherts and obsidians)," show similar trends in size, shape, and function despite the raw material they were made from."Our preliminary results suggest that raw material quality does not dictate Clovis point design.

In other words, despite the difficulties in knapping lower-quality raw materials, Clovis experts were able to use skill to overcome those constraints. This has interesting implications for the technological organization that we are exploring." Written for you by our author Sandee Oster, edited by Lisa Lock, and fact-checked and reviewed by Robert Egan—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive. If this reporting matters to you, please consider a donation (especially monthly). You'll get an ad-free account as a thank-you. More information Briggs Buchanan et al, The Functional Use of Quartz Crystal Points in Clovis Technology, Lithic Technology (2025). DOI: 10.1080/01977261.2025.2473130 © 2026 Science X Network Citation: Why did Clovis toolmakers choose difficult quartz crystal? New study offers clues (2026, April 26) retrieved 27 April 2026 from https://phys.org/news/2026-04-clovis-toolmakers-difficult-quartz-crystal.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.