Pompom agate is a distinctive variety of chalcedony characterized by its spherical, radiating, or 'pompom-like' fibrous growths. It is typically found lining cavities within volcanic host rocks and is highly prized by lapidary artists for its unique patterned internal structures when sliced and polished.
Is this pompom agate?
5-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 pompom agate with a known reference. Pompom Agate sits at Mohs 6.5-7 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Pompom Agate leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Pompom Agate typically shows a waxy luster.
- 4Match the color rangeCompare against the expected color range: white, gray, brown, tan.
- 5Look at form & habitCrystal system: trigonal. Typical habit: botryoidal.
Often confused with
Pompom Agate vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside pompom agate
Minerals reported to co-occur with pompom agate. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SiO₂
- Mohs hardness
- 6.5-7
- Density
- 2.6-2.65 g/cm³
- Streak
- White
- Luster
- Waxy
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Botryoidal
- Cleavage
- None
- Rarity
- Common
- Uses
- Lapidary, Collector, Decorative
- Host rock
- Volcanic Rhyolite Vugs
- Typical price
- $5-50 for small specimens to $200 for large display pieces
Where rockhounds find pompom agate
1 mapped spotsClassic worldwide localities
- Mexico
- USA
Field-hunting tip
Look in volcanic rhyolite vugs country — that is the host setting where pompom agate typically forms. If you start seeing quartz, calcite, goethite in float, you are in the right ground. Field specimens usually show a botryoidal habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Texas — start trip planning there.
Common questions
How do you identify pompom agate?+
Where is pompom agate found?+
Can I find pompom agate in the United States?+
How much is pompom agate worth?+
What rocks look like pompom agate?+
What minerals are found with pompom agate?+
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Find pompom agate on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
