Finger coral is a type of scleractinian coral that forms distinctive, slender branching structures resembling fingers. Collectors look for specimens where the small, star-like polyp pores are well-preserved and clearly visible on the surface. These fossils are common in ancient marine sedimentary environments and are often found agatized or calcified in limestone beds.
Is this finger coral?
4-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch finger coral with a known reference. Finger Coral sits at Mohs 3-4, softer than the next harder reference, harder than the previous one.
- 2Name the organismDecide what left the fossil before worrying about the rock. Organism: Stony coral (genus Porites).
- 3Read the lusterHold the specimen under a strong light. Luster: dull.
- 4Match the color rangeCompare against the expected color range: white, tan, brown, gray.
Often found alongside finger coral
Minerals reported to co-occur with finger coral. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Mohs hardness
- 3-4
- Density
- 2.5-2.8 g/cm³
- Luster
- Dull
- Transparency
- Opaque
- Rarity
- Common
- Uses
- Collector, Decorative, Lapidary
- Host rock
- limestone, sedimentary marine deposits
- Organism
- Stony coral (genus Porites)
Where rockhounds find finger coral
1 mapped spotsClassic worldwide localities
- Florida, USA
- Bahamas
- Caribbean Islands
- Red Sea
- Great Barrier Reef, Australia
Field-hunting tip
Where it forms: limestone, sedimentary marine deposits. If you start seeing calcite, aragonite, quartz in float, you are in the right ground. In the U.S., the densest reported localities are in Florida. Start trip planning there.
More finger coral photos
Common questions
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Find finger coral on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
