Map
showing the distribution of sites with quartz artifacts by watershed
Silicate minerals make up
approximately 90% of the debris in the earth’s 40 plus kilometer thick mantle
which includes granite, basalt, schist and sandstone. In fact, the mineral
quartz is one of the most prolific lithic materials then available to
prehistoric people for making stone tools. For this discussion, the range of
quartz, based largely on diaphanous differences, include crystal,
semi-translucent and opaque or milky, depending on the visual clarity of the specimen.
The chemical composition of quartz (SiO2) is found in other stone tool materials
such as jasper, chert, quartzite and chalcedony. Taken collectively, quartz and its
constituent products was a principal material used to make projectile points
and other cutting tools prior to the advent and development of metallurgy. The
delicate conchoidal fracture pattern on some artifacts made from milky quartz
can be difficult to trace - ask any
lithic analyst who has worked with the stuff.
Some
of the typicalt forms of quartz used by different prehistoric cultures
Here in Pennsylvania, quartz was
collected prehistorically from stream bottoms, floodplains, hillsides and other
locations; wherever erosion managed to release the material from its bedrock source.
Some sites were massive workshops. On such sites the land surface is littered
with broken cobbles, cores and the telltale flaked debris from humans reducing
quartz material to manageable size for transport elsewhere. Other sites consist
only of a thin scatter of flakes and perhaps, one or two projectile points suggesting
only a brief visit to the spot to hunt, re-sharpen tools or just as a place for
the traveler to rest before moving on to the next camp.
Quartz was used throughout the
prehistoric cultural continuum, however, the lithic material was seemingly more
popular during the Late Archaic, Middle and Late Woodland periods which may
have been based on availability rather than cultural preference for quartz as
weapons grade material. It is also likely that quartz was the preferred lithic
type used for tool production when knapping points for certain tasks such as
skinning and butchering animals because of its structurally close grained hardness
where, in fact, other lithic materials might have failed.
The following photos of projectile
points and other quartz tool forms from the State Museum and private collections
are provided for the reader’s benefit. These artifacts are from surface collected
sites in the Susquehanna and Delaware drainages of southeastern Pennsylvania.
Paleoindian
fluted points. Crystal quartz and opaque milky quartz
Middle
Archaic bifurcate points. Semi-translucent and opaque milky quartz
Late
Archaic notched and stemmed points of opaque milky quartz
Early
–Middle Woodland corner notched, basal notched and teardrop-shaped points of
quartz
Late
Woodland Levanna and Madison triangular points of opaque milky and semi-translucent
quartz
Early
stage preforms, side notched scraper and spherically battered hammerstone of
opaque milky quartz
Hafted
biface of opaque milky quartz showing heavy abrasion from repeated ground
impact after 50 atlatl launchings
We hope that you have enjoyed this brief presentation on the
use of quartz and the many different stone tool forms fashioned from it. Please
consult the For Additional Reading Section at the end of the blog for
more information about quartz artifacts and how they were used throughout
prehistory. Join us once again next time for another fascinating topic on
Pennsylvania archaeology.
“Save the Past for the Future”.
For additional reading:
Shultz, Charles H., editor
1999 The Geology of Pennsylvania. Special
Publication 1. Pennsylvania Geological Survey and the Pittsburgh Geological
Society.
Custer, Jay F.
2001 Classification Guide for Arrowheads
and Spearpoints of Eastern Pennsylvania and the Central Middle Atlantic Projectile
Points of Pennsylvania. Pennsylvania Historical and Museum Commission.
Kent, Barry C.
1996 Piney Island and the Archaic of
Southeastern Pennsylvania. Pennsylvania Archaeologist 66(2):1-42.
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