2.9" Polished Slab Petoskey Stone Hexagonaria Coral Fossil Devonian Age Michigan
Location: Michigan, United States
Weight: 0.8 Ounces
Dimensions: 2.9 Inches Long, 1.3 Inches Wide, 0.2 Inches Thick
The item pictured is the one you will receive.
Devonian Age, 350 million years old
Petoskey Stone is a unique rock and fossil, specifically a fossilized rugose coral known as Hexagonaria percarinata. These stones are typically pebble-shaped and are found primarily in the northwestern and northeastern regions of Michigan's Lower Peninsula. They are fragments of a coral reef that existed during the Devonian period, approximately 350 million years ago.
Petoskey stones were formed through glaciation, during which ice sheets plucked stones from the bedrock, grinding down their rough edges and depositing them in new locations. When dry, these stones may appear to be ordinary limestone, but when wet or polished, they reveal a distinctive mottled pattern of six-sided coral fossils.
The fossilized coral, Hexagonaria percarinata, is composed of tightly packed, six-sided corallites, which are the skeletal remains of once-living coral polyps. The center of each polyp served as its mouth, surrounded by tentacles that extended outward to capture food. The hexagonal shape of each corallite and the thin radial lines radiating from the dark central “eye” are unique features that make these fossils instantly recognizable and highly valued by collectors.
Petoskey stones can be found on numerous beaches and inland locations throughout Michigan, with many of the most popular sites stretching from Traverse City to Petoskey along Lake Michigan. The movement of frozen lake ice during the winter is thought to reveal new stones each spring, making this the prime time for collectors.
Well-known locations for finding Petoskey stones include Petoskey State Park, Magnus City Park Beach, and Solanus Mission Beach. In addition to beaches, rockhounds often search cut roadbeds, gravel pits, and farmers’ fields for these fossils. The best time to collect Petoskey stones is typically in the spring, after the ice has shifted the shoreline and uncovered fresh specimens.
