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Named stone

Hardyston jasper

Also called Pennsylvania jasper, Reading Prong jasper, Hardyston Formation jasper

A kind of jasper

Hardyston jasperJasperNortheast

Description

Hardyston jasper is the red, yellow and brown jasper of southeastern Pennsylvania. It sits in pods and seams in the upper Hardyston Formation, where hot silica-rich water replaced the original quartzite. The luster is waxy, and pieces often carry clear quartz veins or bubbly chalcedony coatings, sometimes orange or purple. Texture ranges from even to brecciated or dendritic. Good stone improves with heating, while poor stone stays grainy and dull. People quarried it for more than 10,000 years: Pennsylvania's historic preservation office counts 176 precontact sites in the Hardyston Jasper District, and the stone travelled to Paleoindian camps in New York and New England. Jasper Perkiomen and other broadspear points are well known products.

How to identify it

Colour
Red, yellow and brown (Ebright); the Maryland guide describes jasper in general as red, yellow, orange or brown from iron.
Texture
Homogeneous to brecciated or dendritic patterned (Ebright).
Luster
Lustrous and waxy.
Inclusions
Clear quartz veins or botryoidal chalcedony coatings, occasionally orange or purple.
Heat treatment
Responds well to heat treatment; lower-quality, grainy and dull material does not improve as much (Ebright). The Maryland guide says heating jasper generally makes it waxier and redder.

Geology

Jasper in the upper levels of the Hardyston Formation, forming discontinuous pods that are most common in the eastern part of the formation. Hydrothermal replacement of the quartzite parent rock created the jasper. The quarry sites follow a jasper seam within the formation.

Where it comes from

Northeast, Mid-Atlantic

States

Quarries and outcrops

  • Hardyston Jasper District, southeastern Pennsylvania (176 precontact sites defined by Anthony and Roberts in 1988)
  • Berks County, Pennsylvania (the sample in the Virginia guide came from south of Bowers)
  • Interstate 78 corridor, where PennDOT found many quarry sites

Used by

  • Paleoindian: Pennsylvania jasper tools occur at the West Athens Hill site in New York (Funk) and in Northeast fluted-point assemblages (Kitchel)
  • Quarried for over 10,000 years (Pennsylvania SHPO); jasper Perkiomen and broadspear points are shown in the State Museum of Pennsylvania collection

Look-alikes

Stones that are easy to confuse with Hardyston jasper.

  • Iron Hill (Newark) jasper from Delaware: chlorite-rich, yellow-brown, sometimes banded chalcedony (Delaware DOT glossary)
  • Flint Run jasper (Virginia): brown and yellow with red, green, blue or gray streaks
  • Other red-yellow-brown jaspers of the Mid-Atlantic; a Hardyston 'chalcedony' (Pennsylvania microquartzite) is listed separately by the Maryland guide

Sources

  1. Ebright, Carol. 1999 (updated 2023). Pennsylvania Jasper. Virginia Department of Historic Resources, Lithics (Projectile Points and Lithics guide).dhr.virginia.gov (opens in a new tab)
  2. Walczesky, Kristen. 2023 (4 October). Quarrying our Data for Quarry Districts. Pennsylvania Historic Preservation (blog of the Pennsylvania State Historic Preservation Office).pahistoricpreservation.com (opens in a new tab)
  3. Maryland Archaeological Conservation Laboratory. Jasper. Diagnostic Artifacts in Maryland: Common Stone Types (Jefferson Patterson Park and Museum).apps.jefpat.maryland.gov (opens in a new tab)
  4. Delaware Department of Transportation. Archaeology glossary: Jasper.deldot.gov (opens in a new tab)
  5. Funk, Robert E. 2004. An Ice Age Quarry-Workshop: The West Athens Hill Site Revisited. New York State Museum Bulletin 504. University of the State of New York, Albany.exhibitions.nysm.nysed.gov (opens in a new tab)
  6. Kitchel, Nathaniel R. 2024. Facing the Forest: Climate Change and Human Adaptation Across the Pleistocene-Holocene Transition in Northern New England and Eastern Canada. PaleoAmerica (online 28 Oct 2024). doi:10.1080/20555563.2024.2414630.par.nsf.gov (opens in a new tab)
  7. U.S. Geological Survey, National Geologic Map Database. Geolex: Hardyston publications.ngmdb.usgs.gov (opens in a new tab)

Points made from this stone

All materials