Archaeology Lab (ANTL 207)
Introduction to Artifacts
Artifact – anything made, modified or utilized by humans.
Artifacts are material remains left behind by people. They make up one of the most
important datasets used by archaeologists to interpret past human behaviour. In the
archaeology lab artifacts are divided initially by material type – pottery, stone (lithics),
metal, glass, shell, bone, etc. These are the most common artifact categories. Further,
more refined categories exist with each of these, as you’ll see below.
Lithics – stones. The term “lithic” comes from the Greek lithos meaning stony. ‘Lithic’
is an adjective, which is why you see the term before the word ‘tool’ or ‘artifact.’ Stone
tools are the oldest artifacts that have survived in the archaeological record. Like
pottery, stone preserves indefinitely so archaeologists working on prehistoric sites tend
to find lots of it. But stone tools have been around much, much longer than ceramic
artifacts. In fact, the use of stone tools predates the evolution of modern Homo sapiens
by more than a million years. The earliest stone tools come from Olduvai Gorge in
Africa and date to approximately 2.5 million years ago (mya). From that time up to the
adoption of pottery making around 14,000 B.C. in Japan the archaeological record is
dominated by stone.
This isn’t really surprising since humans have long understood the tremendous utility of
this unique material – a lump of stone could be worked (flaked/chipped) to create a
sharp cutting edge and then re-sharpened many times. Until recently hunting-gathering
groups have flaked lumps of stone to create spear points, arrow points (arrowheads),
choppers, scrapers, drills and many other lithic tools. Later, farming peoples realized
how stone could be utilized to grind grains like wheat and corn, and since the advent of
farming in Mesopotamia around 10,000 years ago humans have been creating
groundstone tools.
Flaked or chipped stone – rocks that can be flaked (chipped) so that they have a sharp
edge include flint, chert, obsidian (volcanic glass), jasper, rhyolite, quartz, quartzite,
petrified wood and even glass. The creation of flaked stone objects is a subtractive
process, whereby material is removed from a mass of stone. This stands in contrast to
ceramic technology, which is additive by nature. The principal goal of lithic reduction for
the ‘flintkanpper’ is to fracture the lithic material in a controlled and predictable way in
order to a) not waste time and material and 2) achieve the desired shape.
Obsidian blades
Reduction involves the removal of lithic material, usually from a core - the mass of stone
from which flakes are removed. There are two basic flaking techniques: percussion and
pressure.
Persussion flaking – striking the core with a hammerstone or against a fixed stone anvil;
reltively large flakes are removed and large flake scars (negative impressions of flakes)
can be seen on the core
 Direct percussion – the hammer strikes the stone directly
 Indirect percussion – a bone, antler, or wood punch is placed on an edge of the
core and struck with a hammerstone
Pressure flaking – steady pressure exerted on a punch to detach flakes; generally small
flakes are removed
Chert biface from the Maya site of Lamanai, Belize
Groundstone A general or catch-all category for stone that is shaped by pecking (pulverizing) or
abrading (by grinding, smoothing, polishing and drilling). Some types of stone, such as
granite or basalt, will not flake well due to their mineral structure. The softer varieties
of such stones, including soapstone (steatite), alabaster, turquoise and lapis lazuli, were
(and still are) shaped primarily by cutting methods. Objects made from tough stones,
such as granite, can be shaped by pecking – hitting the stone with a hammerstone at
approximately a 90° angle to create small pits in the stone. Abrading or grinding creates
a smooth, even surface and often involves the use of small, hard particles such as sand
as an additional abrasive along with water or oil. It is thought that jade, a mineral
harder than steel, was shaped in this manner by precolumbian peoples such as the
Maya.
Mano and metate – precolumbian groundstone tools
Jade fragment from the Maya site of Lamanai, Belize
Note the high degree of polishing
Pottery – any type of baked clay containing a tempering agent (aplastic inclusion). So
pottery is made up of clay, which is plastic (can be shaped) and temper, the aplastic
inclusion. The clay and the temper together are referred to as the paste. Temper is
added by the potter to the clay to give the clay greater strength and prevent shrinkage
by the wet clay as it dries. Tempering materials or agents include grit (rock fragments),
sand, ground or powdered shell fragments, grog (broken pottery) and a variety of
organic agents, including Spanish Moss, plant fibers, straw, and other organic materials
that burn out when the pottery is fired. Without tempering agents clay tends to shrink
and crack during drying and will fall apart quickly after firing.
Once people from different cultures throughout the world understood how to make
fired clay containers they usually made LOTS of them. Also, because of how it is made
pottery is very durable – it lasts almost indefinitely in the archaeological record. It is for
these two reasons that archaeologists often find lots of pottery, and a lot of lab work
involves processing and analyzing pot sherds.
In the archaeology lab pottery is classified by paste and surface treatment. Potsherds
are broken pieces of a pot. It’s pretty rare for archaeologists to find whole ceramic
vessels, unless one is lucky enough to find a tomb. Looters target pyramids in the Maya
area and elsewhere because they know that whole ceramic vessels were often interred
in the tombs of Maya kings and queens, and these vessels, often with beautiful
polychrome (multi-colored) designs and hieroglyphs, can fetch many thousands of
dollars on the illicit international antiquities market. So unless you’re excavating a tomb
or have found a cache of vessels more than likely you’ll be bringing back sherds to the
archaeology lab.
Pot sherds are usually classified as rim sherds, neck sherds and body sherds, depending
on where on the original pot they originated. Rim sherds provide the most stylistic
information, since they convey quite a lot about the overall shape of the vessel. The
color of the paste and surface of a pot provide information on how the vessel was fired.
The shape and temper of a vessel give clues concerning its function; consistency in
vessel shape, size and tempering give clues about how a pot was made and how a
society is organized. Archaeologists are often obsessive about pottery, in part for the
two reasons listed above (there’s often a lot of it made in prehistoric times and it
preserves extremely well), but more importantly because a lot of information can be
extracted from a single pot sherd.
Drawing of rim of Early Postclassic Period (ca AD 122-1400) ceramic vessel
From the Maya site of Lamanai, Belize
Historic potsherds -
19th century ceramic artifacts from Nauvoo, Illinois
Precolumbian potsherds -
Ceramic rim sherds from the Maya site of Lamanai, Belize
Late Classic Period (AD 600-900)
Daub is a special category of pottery that was originally clay tempered with grass, straw
or reeds, plastered atop a framework of sticks, and allowed to bake in the sun. This
framework or latticework of sticks and mud is called wattle and daub architecture by
archaeologists. Normally, daub dissolves over the course of time and does not preserve.
But if a wattle and daub structure burns the daub is fired by accident and becomes a
type of pottery. It then preserves extremely well in the archaeological record.
Metal – metal is found at some prehistoric sites but often is associated mainly with
historic period sites. Metals found at archaeological sites include iron, copper, gold
silver and lead, among others.
Iron is often very rusty and can be challenging to distinguish from soil using the naked
eye. Some of the rust can be removed by brushing, and in most archaeology labs dry
brushing is the initial step in processing iron objects such as nails and other hardware.
Further processing of iron artifacts requires reverse electrolysis, a technique that lifts
rust particles off an object.
Copper is distinguished in archaeological contexts by its green patina, which helps to
preserve organic materials the copper touches. Cloth and fibers might be found
embedded in copper artifacts, so copper should be checked very carefully once it is
brought to the archaeology lab. Copper needs little conservation and the green patina
should not be removed unless further conservation efforts are undertaken as the patina
actually protects the artifact from further breakdown.
Copper axe in three pieces from the Maya site of Lamanai, Belize
Lead is heavy, soft and does not corrode. It can occur in cubic crystals (galena) or be
shaped into bullets, such as the famous minnie balls from the Civil War. Silver and gold
are fairly rare, as people were careful to take their valuables with them when they
abandoned sites, and sometimes silver and gold were melted down to form new metal
objects. Silver is covered with black corrosion, but gold does not corrode. If gold or
silver are found at a site or are in an archaeology lab be very careful not to discuss these
with people other than archaeologists because if their presence (or even suspected
presence) is one of the main reasons archaeological sites are looted and labs are broken
into by thieves.
Wood, Bone, Antler and Shell – depending on soil conditions and weathering agents
certain sculpted organic materials such as these might be preserved in the
archaeological record. Simple digging sticks or clubs may have been the earliest objects
created and used by early human ancestors, long before the earliest preserved artifacts,
stone tools. Yet the addition of stone tools to the toolkit of our earliest ancestors must
have greatly increased their ability to cut and shape larger pieces of wood as well as
bone, ivory, antler and shell. As you can imagine, conservation is key to long-term
preservation of organic artifacts once they are excavated from the ground or from the
sea. Organic materials such as these are best handled by professional conservators,
such as those that work at the Getty Institute and the Smithsonian Institution.
Carved (incised) bone tube from the Maya site of Lamanai, Belize
Late Classic Period (ca. 700-900 AD)
Worked (drilled and abraded) marine shell from
the Maya site of Lamanai, Belize
Glass – glass is melted silica that can be formed into whatever shape is desired by the
glassblower. In North America it is found in historic (post-contact) contexts, but in the
Old World it dates to the Old Kingdom in Egypt. Glass bottles and other types of vessels
can be dated typologically. Over time, water penetrates the interior of the glass,
causing the glass to flake into layers – a kind of patina. Left untreated, glass will
eventually break down into little flakes.
Wine bottle, early 18th century, Virginia
19th century bottles from Essex, England