sedimentary
Coral Fossil (Scleractinia)
Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)
Hardness: 3-4 (Mohs scale); Color: White to light tan; Luster: Dull to earthy; Structure: Hexagonal or colonial coralite patterns; Cleavage: None/Fragmental; Specific Gravity: 2.5-2.7
- Hardness
- 3-4 (Mohs scale)
- Color
- White to light tan
- Luster
- Dull to earthy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3-4 (Mohs scale); Color: White to light tan; Luster: Dull to earthy; Structure: Hexagonal or colonial coralite patterns; Cleavage: None/Fragmental; Specific Gravity: 2.5-2.7
Formation & geological history
Formed through the accumulation and petrification of coral polyps' skeletons in marine environments. Over time, the organic material is replaced or filled with minerals, typically calcite, throughout the Holocene or older geological epochs.
Uses & applications
Used primarily in home decor, jewelry (beads), aquarium landscaping, and as educational specimens for fossil collectors.
Geological facts
These fossils are the remains of ancient reef-building organisms. While they look like rocks, they are the preserved biological architecture of marine animals. Some fossilized corals (like Petoskey stones) are millions of years old.
Field identification & locations
Identify by looking for the distinct 'honeycomb' or star-like patterns of the coralites. Commonly found on beaches in tropical regions or inland where ancient seas once existed. Collectors should look for distinct radial symmetry in each hole.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone (Quartz-rich)
Arenite (SiO2)
sedimentary
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
sedimentary