An agatized fern bud is a fossilized botanical structure in which organic material has been replaced by microcrystalline quartz. It usually appears as a distinct rounded or whorled nodular growth, found within sedimentary deposits or volcanic ash beds.
Is this agatized fern bud?
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 agatized fern bud with a known reference. Agatized Fern Bud 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. Agatized Fern Bud leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Agatized Fern Bud typically shows a waxy luster.
- 4Match the color rangeCompare against the expected color range: brown, tan, gray, white, black, red.
- 5Look at form & habitCrystal system: trigonal. Typical habit: botryoidal.
Often confused with
Agatized Fern Bud vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside agatized fern bud
Minerals reported to co-occur with agatized fern bud. 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
- 2.6-2.7 g/cm³
- Streak
- White
- Luster
- Waxy
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Botryoidal
- Cleavage
- None
- Rarity
- Uncommon
- Uses
- Collector, Lapidary, Decorative
- Host rock
- Sedimentary Strata
Where rockhounds find agatized fern bud
1 mapped spotsClassic worldwide localities
- USA (Utah)
- USA (Colorado)
- USA (Wyoming)
Field-hunting tip
Look in sedimentary strata country, the host setting where agatized fern bud typically forms. If you start seeing quartz, calcite, barite 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 agatized fern bud?+
Where is agatized fern bud found?+
Can I find agatized fern bud in the United States?+
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Find agatized fern bud on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
