Begin Main Content Area

Identifying and Collecting

Pennsylvania is rich in geological variety. All three rocks types -- igneous, metamorphic, and sedimentary -- are present in the state.

More than 275 minerals have been verified from Pennsylvania, and thousands of fossil plant and animal species have been found.


Fossils are remains, traces, or imprints of any plant or animal from a past geologic or prehistoric time that has been preserved in the earth’s crust.

There are many fossils in the rocks of Pennsylvania, and DCNR offers resources to help you identify what you find.

Fossil Plates

Fossil plates can help you determine what kinds of fossils you find while exploring the outdoors.

DCNR’s Bureau of Geological Survey recommends that the provided plates be printed 4.5 inches wide and approximately 7 inches high to maintain the correct scale factor indicated for each fossil.

Plate illustrations are by John G. Kuchinski, Albert E. Van Olden, and James H. Dolimpio.

Pennsylvania State Fossil

Phacops rana photo
Pennsylvania’s state fossil is of an organism known as Phacops rana, a type of trilobite. Trilobites are an extinct category of joint-legged animals (Arthropods) related to crabs, lobsters, shrimps, spiders, and insects.

Trilobites are among the most complex of all the animals that ever existed without backbones. Their traits included the following:

  • Well-developed nervous systems
  • Large antennae
  • Many appendages for swimming, walking, or feeding
  • Hard outer skeletons
  • Large eyes and the most ancient vision system known to scientists

Trilobites are a common fossil in many of the early to middle Paleozoic rocks of central Pennsylvania. These rocks range in age from 541 to 359 million years old.

Complete fossil specimens are rare because a trilobite’s rigid outer skeletal segments were joined by flexible organic connections that decayed on the death of the animal. Currents and scavengers then served to separate the skeletal parts.

The abundance of trilobite skeletal parts in the fossil record was enhanced by the fact that the animals grew by casting off their outer skeleton in a series of molt stages. One animal probably produced 10 to 12 potentially preservable skeletons in its lifetime.

Phacops rana is found in Pennsylvania's Devonian-age rocks (rocks between 419 and 359 million years old).

Explore the Pennsylvania outdoors and see if you can spot our state fossil!

Rocks and Minerals

Rocks and minerals are the base of Pennsylvania’s diverse landscape as well as the source of its rich economic heritage.

Identifying and collecting these rocks and minerals are simple activities that can be done with family and do not require much equipment. Whether exploring outdoors or visiting museum collections, Pennsylvania provides opportunities to learn more about its minerals and rocks.

Rock and Mineral Clubs

Rock and mineral clubs across the state can provide guidance to the novice collector and comradery to the experienced collector.

Clubs open the gates of quarries that are otherwise not accessible to collectors. For more information, see a list of clubs in Pennsylvania.

Rock Boxes

Rock Box photo
Rock boxes help with rock identification and observation. The DCNR Bureau of Geological Survey, the Pennsylvania Department of Education, and the Pennsylvania Aggregates and Concrete Association all contribute to the creation of the rock boxes.

A box containing 12 samples of Pennsylvania rocks and spaces for six more of your own rocks is $15.00. A classroom kit, which contains bags of 30 samples for each of the 12 rock types, is available for $30.00.

There is a $4.95 shipping and handling charge for each item ordered. Proceeds will be used to buy materials for future boxes and provide other outreach services.

Ordering Rock Boxes

Anyone can order DCNR’s rock boxes. Fill out the order form (PDF) and include a check made out to the “Field Conference of Pennsylvania Geologists.” Shipping address cannot be a P.O. Box.

Please send the order form and payment to the following address:

Rock Boxes
Pennsylvania Geological Survey
3240 Schoolhouse Rd
Middletown, PA 17057–3534