Crinoid stems are fossilized segments of marine echinoderms often found as stackable, wheel-like discs in limestone deposits. They are frequently identified by their central pentagonal or circular hole and are a staple find for amateur paleontologists in Paleozoic marine strata.

Hardness

3-4

Mohs

Luster

Dull

Streak

White

Transparency

Opaque

fossilcommon

Crinoid Stems

Also: Indian beads, Stone beads, Crinoid ossicles

Hardness: 3-4
Luster: Dull
Streak: White
Transparency: Opaque

Is this crinoid stems?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch crinoid stems with a known reference. Crinoid Stems sits at Mohs 3-4, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Crinoid Stems leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Crinoid Stems typically shows a dull luster.
4
Match the color range
Compare against the expected color range: gray, white, tan, brown.
5
Look at form & habit
Typical habit: cylindrical segments.

Often found alongside crinoid stems

Minerals reported to co-occur with crinoid stems. Spotting these in float or country rock is a strong cue you are in the right ground.

Calcite
mineral · Mohs 3

All properties

Chemical formula: CaCO₃
Mohs hardness: 3-4
Density: 2.6-2.7 g/cm³
Colors: Gray White Tan Brown
Streak: White
Luster: Dull
Transparency: Opaque
Crystal habit: Cylindrical Segments
Cleavage: None
Rarity: Common
Uses: Collector, Decorative, Educational
Host rock: Limestone
Typical price: $1-20 per specimen

Where rockhounds find crinoid stems

3 mapped spots

Classic worldwide localities

Indiana, USA
Ohio, USA
United Kingdom
Germany
Missouri, USA

Field-hunting tip

Look in limestone country, the host setting where crinoid stems typically forms. If you start seeing calcite, brachiopods, bryozoans in float, you are in the right ground. Field specimens usually show a cylindrical segments habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Texas, Michigan. Start trip planning there.

Browse 3 U.S. spots for crinoid stems →

Common questions

How do you identify crinoid stems?+

Mohs hardness is 3-4. It typically shows a dull luster. The streak is white. Common colors include gray, white, tan, brown.

Where is crinoid stems found?+

Notable localities include Indiana, USA; Ohio, USA; United Kingdom; Germany; Missouri, USA.

Can I find crinoid stems in the United States?+

RockHoundR maps 3 crinoid stems rockhounding spots across 2 U.S. states. The top states are Texas, Michigan.

How much is crinoid stems worth?+

Typical asking prices fall in the range of $1-20 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What minerals are found with crinoid stems?+

Crinoid Stems commonly co-occurs with Calcite, Brachiopods, Bryozoans. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does crinoid stems form in?+

Crinoid Stems typically forms in limestone. Working float back to the host body is the standard way to chase a fresh occurrence.

What is crinoid stems used for?+

Crinoid Stems is used in collector, decorative, educational.

Find crinoid stems on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.