Dig Deeper Blog,  Exhibits

Dig Deeper: How Are Stone Tools Made?

Dig Deeper is a monthly blog focusing on the basics of archaeology by taking a closer look at the exhibition Archaeology 101, which is currently featured at the Center.


Now that we have discussed the different ways that archaeologists figure out who may have made the artifacts that are uncovered during an excavation, let’s dig deeper to learn about making stone tools.

What Cultures Used Stone Tools?

Throughout history, stone tools have been made by different cultures all over the world. Before metal tools came about, stone was the most used raw material for tool making for more than three million years. Known as the Stone Age, this period ended once China, Europe, the Middle East, and Africa discovered how to make metal implements. In the Americas, the Stone Age did not end until colonialism when European settlers arrived and introduced steel and iron tools to the indigenous cultures.

Types of Stone Tools

This is a chipped stone projectile point excavated in Otay Mesa. Types of projectile points changed over time as technology advanced and indigenous peoples shared ideas with one another.

At the Center, we preserve and protect hundreds of thousands of stone tools. There are two generally recognized types: chipped stone and ground stone. They are named for their method of production. Chipped stone tools are made by carefully chipping away parts of the stone to make the desired tool. This is called flintknapping. These types of tools can be made with very sharp edges and points and some examples are: scrapers, projectile points, and knives. Chipped stone tools were used for hunting, food preparation, and building homes or shelter spaces.

Similar to what we still use today, these ground stone tools are a prehistoric mortar and pestle.

Ground stone tools are made by grinding, shaping, and smoothing the stone into the desired tool shape. Ground stone tools were used less for hunting and more for the grinding of food or other substances, such as color dyes. Manos are the hand tools that would be used to grind the food into the metate, which is the larger stone base that would hold food while being ground. Ground stone tools that we still use frequently today are mortar and pestles. While not always made of stone, many of them are and are used to grind things like spices and nuts. Weaponry tools could also be created by using ground stone, such as axes or clubs. Both ground stone and chipped stone tools would often be attached to wood to make artifacts like a throwing spear or arrows.

Variations in Tool Making

Tool making change with time and this is another way that archaeologists are able to identify whom the tools they find belonged to. Different tools were used by different cultures, largely depending on the region that people lived and the geological specimens that were available to them at the time. The materials used when making chipped stone and ground stone tools varied but typically a stronger stone would be used to make ground stone, like granitic rock. Materials like obsidian, or more glass-like rock types, would be used to make chipped stone.

Used for grinding foods and other substances, a mano and metate are commonly found ground stone tools.

How Are Stone Tools Identified?

Stone tools have characteristics that distinguish them from natural stone. Ground stone manos for example, are smooth from the grinding wear from use over time. Chipped stone tools can be identified and separated from naturally broken stone by identifying the bulb of percussion. The bulb of percussion is formed when a stone is struck with another stone tool. The energy that enters the stone is strong and then tapers off so that the resulting flake is thicker and at the top and thinner towards to bottom.

Up Next

What about all of the flakes that are created when making a chipped stone tool? Do archaeologists care about those? Come back next month to dig even deeper and learn what debitage is!

By Jessica McPheters, Collections Manager

Learn More

For more information on stone tool making, visit the Smithsonian Museum of Natural History’s site What does it mean to be human?

Archaeology 101 Exhibit

Volunteers work in the Center’s Research Library, cataloguing materials and organizing on a computer-based system.

Marketing and Administrative Volunteers assist the Development Office or Administration Office with data entry, updating marketing materials and clerical tasks. Computer experience is a plus.

Docents welcome visitors and answer general questions regarding the Center and exhibits. Docents staff the gift shop and help out with administrative and curatorial tasks.

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Volunteer provide support for K-12 programs offered at the Center. These are fun, hands-on programs that kids really enjoy. Teaching experience is a plus, but not required. Background checks are required.


With the assistance of Center staff, the intern will use photogrammetry to prepare one or more archaeological collections for digital preservation, as well as create a virtual museum exhibit for our Public Archaeology department. Per approval, special projects of the intern’s choosing are also available. During the research and planning, the intern will receive guidance as appropriate to their selected project. Prospective interns should already be familiar with photogrammetric procedures, and Agisoft Metashape.

Collections Management

With the assistance of Center staff, the intern will prepare one or more archaeological collections for curation. During the course of the internship, the intern will learn to identify artifacts and ecofacts common to the San Diego region, including lithics, ceramics, historical objects, and faunal, botanical, and mineral specimens. Center staff will instruct the intern on archaeological laboratory procedures such as basic artifact analysis, manual and computer cataloguing, storage requirements, and preventative conservation. In addition, the intern will become familiar with historical trends in archaeological practice in the San Diego area and will be introduced to current legal and ethical issues in archaeological curation as well as the concerns and rights of culturally affiliated groups with regard to archaeological materials.

Development and Marketing

Under the direction of Center staff, the intern will support the department in various activities, including, but not limited to, fundraising and grant research; e-newsletter development; social media marketing; and website maintenance. This internship will give the intern valuable, real-world experience in non-profit fundraising and marketing.

Geographical Information Systems in Archaeology

Prospective Interns must have completed three courses: Introduction to GIS, GIS Database Management, and Intermediate/Advanced Methods in GIS. The intern will be assigned a project where they will create shapefiles and maps for curated archaeological collections, museum exhibits, and/or public outreach using ArcGIS 10.6. Center staff will instruct the intern on archaeological GIS laboratory procedures such as computer cataloguing, storage requirements, and database management.

Library Science

With the assistance of Center staff, the intern will arrange and catalog materials in the Center’s library. During the course of the internship, the intern will take a leading role in the cataloging, sorting and storing of research files and creating user guides for these collections. Center staff will instruct the intern on archival procedures, computer cataloging, storage requirements, and preventative conservation.

Public Archaeology

Harness your passion for Public Archaeology and gain hands-on experience with K-12 museum field trips, lectures, and public outreach. Additional projects may include creating virtual museum exhibits and activities, assisting in the development and implementation of K-12 curricula programs, planning and presenting public facing content, or educational field trip content of your own design. Must be able to pass a Live Scan.